CVE-2023-53500 (GCVE-0-2023-53500)
Vulnerability from cvelistv5 – Published: 2025-10-01 11:45 – Updated: 2026-10-15 21:41
VLAI
EPSS
VEX
Title
xfrm: fix slab-use-after-free in decode_session6
Summary
In the Linux kernel, the following vulnerability has been resolved:
xfrm: fix slab-use-after-free in decode_session6
When the xfrm device is set to the qdisc of the sfb type, the cb field
of the sent skb may be modified during enqueuing. Then,
slab-use-after-free may occur when the xfrm device sends IPv6 packets.
The stack information is as follows:
BUG: KASAN: slab-use-after-free in decode_session6+0x103f/0x1890
Read of size 1 at addr ffff8881111458ef by task swapper/3/0
CPU: 3 PID: 0 Comm: swapper/3 Not tainted 6.4.0-next-20230707 #409
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014
Call Trace:
<IRQ>
dump_stack_lvl+0xd9/0x150
print_address_description.constprop.0+0x2c/0x3c0
kasan_report+0x11d/0x130
decode_session6+0x103f/0x1890
__xfrm_decode_session+0x54/0xb0
xfrmi_xmit+0x173/0x1ca0
dev_hard_start_xmit+0x187/0x700
sch_direct_xmit+0x1a3/0xc30
__qdisc_run+0x510/0x17a0
__dev_queue_xmit+0x2215/0x3b10
neigh_connected_output+0x3c2/0x550
ip6_finish_output2+0x55a/0x1550
ip6_finish_output+0x6b9/0x1270
ip6_output+0x1f1/0x540
ndisc_send_skb+0xa63/0x1890
ndisc_send_rs+0x132/0x6f0
addrconf_rs_timer+0x3f1/0x870
call_timer_fn+0x1a0/0x580
expire_timers+0x29b/0x4b0
run_timer_softirq+0x326/0x910
__do_softirq+0x1d4/0x905
irq_exit_rcu+0xb7/0x120
sysvec_apic_timer_interrupt+0x97/0xc0
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:intel_idle_hlt+0x23/0x30
Code: 1f 84 00 00 00 00 00 f3 0f 1e fa 41 54 41 89 d4 0f 1f 44 00 00 66 90 0f 1f 44 00 00 0f 00 2d c4 9f ab 00 0f 1f 44 00 00 fb f4 <fa> 44 89 e0 41 5c c3 66 0f 1f 44 00 00 f3 0f 1e fa 41 54 41 89 d4
RSP: 0018:ffffc90000197d78 EFLAGS: 00000246
RAX: 00000000000a83c3 RBX: ffffe8ffffd09c50 RCX: ffffffff8a22d8e5
RDX: 0000000000000001 RSI: ffffffff8d3f8080 RDI: ffffe8ffffd09c50
RBP: ffffffff8d3f8080 R08: 0000000000000001 R09: ffffed1026ba6d9d
R10: ffff888135d36ceb R11: 0000000000000001 R12: 0000000000000001
R13: ffffffff8d3f8100 R14: 0000000000000001 R15: 0000000000000000
cpuidle_enter_state+0xd3/0x6f0
cpuidle_enter+0x4e/0xa0
do_idle+0x2fe/0x3c0
cpu_startup_entry+0x18/0x20
start_secondary+0x200/0x290
secondary_startup_64_no_verify+0x167/0x16b
</TASK>
Allocated by task 939:
kasan_save_stack+0x22/0x40
kasan_set_track+0x25/0x30
__kasan_slab_alloc+0x7f/0x90
kmem_cache_alloc_node+0x1cd/0x410
kmalloc_reserve+0x165/0x270
__alloc_skb+0x129/0x330
inet6_ifa_notify+0x118/0x230
__ipv6_ifa_notify+0x177/0xbe0
addrconf_dad_completed+0x133/0xe00
addrconf_dad_work+0x764/0x1390
process_one_work+0xa32/0x16f0
worker_thread+0x67d/0x10c0
kthread+0x344/0x440
ret_from_fork+0x1f/0x30
The buggy address belongs to the object at ffff888111145800
which belongs to the cache skbuff_small_head of size 640
The buggy address is located 239 bytes inside of
freed 640-byte region [ffff888111145800, ffff888111145a80)
As commit f855691975bb ("xfrm6: Fix the nexthdr offset in
_decode_session6.") showed, xfrm_decode_session was originally intended
only for the receive path. IP6CB(skb)->nhoff is not set during
transmission. Therefore, set the cb field in the skb to 0 before
sending packets.
Severity
7.3 (High)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-15 21:35 UTC
Assigner
References
7 references
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
f855691975bb06373a98711e4cfe2c224244b536 , < da4cbaa75ed088b6d70db77b9103a27e2359e243
(git)
Affected: f855691975bb06373a98711e4cfe2c224244b536 , < db0e50741f0387f388e9ec824ea7ae8456554d5b (git) Affected: f855691975bb06373a98711e4cfe2c224244b536 , < bafa236380816b41b2c4c6970d9067fefa4a6c9e (git) Affected: f855691975bb06373a98711e4cfe2c224244b536 , < 44b3d40967009304617a7a6486490c1d6c12f899 (git) Affected: f855691975bb06373a98711e4cfe2c224244b536 , < 0d27567fde5be5f0edc2db5c110142b7915b8fa8 (git) Affected: f855691975bb06373a98711e4cfe2c224244b536 , < 86f15300a22656db3fa8c8967defbcd24fac4d37 (git) Affected: f855691975bb06373a98711e4cfe2c224244b536 , < 53223f2ed1ef5c90dad814daaaefea4e68a933c8 (git) |
guessed | |
| Linux | Linux |
Affected:
3.19
Unaffected: 0 , < 3.19 (semver) Unaffected: 4.19.293 , ≤ 4.19.* (semver) Unaffected: 5.4.255 , ≤ 5.4.* (semver) Unaffected: 5.10.192 , ≤ 5.10.* (semver) Unaffected: 5.15.128 , ≤ 5.15.* (semver) Unaffected: 6.1.47 , ≤ 6.1.* (semver) Unaffected: 6.4.12 , ≤ 6.4.* (semver) Unaffected: 6.5 , ≤ * (original_commit_for_fix) |
guessed |
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2023-53500",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-10-15T21:35:03.965341Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-10-15T21:41:29.274Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/xfrm/xfrm_interface_core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "da4cbaa75ed088b6d70db77b9103a27e2359e243",
"status": "affected",
"version": "f855691975bb06373a98711e4cfe2c224244b536",
"versionType": "git"
},
{
"lessThan": "db0e50741f0387f388e9ec824ea7ae8456554d5b",
"status": "affected",
"version": "f855691975bb06373a98711e4cfe2c224244b536",
"versionType": "git"
},
{
"lessThan": "bafa236380816b41b2c4c6970d9067fefa4a6c9e",
"status": "affected",
"version": "f855691975bb06373a98711e4cfe2c224244b536",
"versionType": "git"
},
{
"lessThan": "44b3d40967009304617a7a6486490c1d6c12f899",
"status": "affected",
"version": "f855691975bb06373a98711e4cfe2c224244b536",
"versionType": "git"
},
{
"lessThan": "0d27567fde5be5f0edc2db5c110142b7915b8fa8",
"status": "affected",
"version": "f855691975bb06373a98711e4cfe2c224244b536",
"versionType": "git"
},
{
"lessThan": "86f15300a22656db3fa8c8967defbcd24fac4d37",
"status": "affected",
"version": "f855691975bb06373a98711e4cfe2c224244b536",
"versionType": "git"
},
{
"lessThan": "53223f2ed1ef5c90dad814daaaefea4e68a933c8",
"status": "affected",
"version": "f855691975bb06373a98711e4cfe2c224244b536",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/xfrm/xfrm_interface_core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.19"
},
{
"lessThan": "3.19",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "4.19.*",
"status": "unaffected",
"version": "4.19.293",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.4.*",
"status": "unaffected",
"version": "5.4.255",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.192",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.128",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.47",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.4.*",
"status": "unaffected",
"version": "6.4.12",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.5",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "4.19.293",
"versionStartIncluding": "3.19",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.4.255",
"versionStartIncluding": "3.19",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.10.192",
"versionStartIncluding": "3.19",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15.128",
"versionStartIncluding": "3.19",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.47",
"versionStartIncluding": "3.19",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.4.12",
"versionStartIncluding": "3.19",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.5",
"versionStartIncluding": "3.19",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: fix slab-use-after-free in decode_session6\n\nWhen the xfrm device is set to the qdisc of the sfb type, the cb field\nof the sent skb may be modified during enqueuing. Then,\nslab-use-after-free may occur when the xfrm device sends IPv6 packets.\n\nThe stack information is as follows:\nBUG: KASAN: slab-use-after-free in decode_session6+0x103f/0x1890\nRead of size 1 at addr ffff8881111458ef by task swapper/3/0\nCPU: 3 PID: 0 Comm: swapper/3 Not tainted 6.4.0-next-20230707 #409\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014\nCall Trace:\n\u003cIRQ\u003e\ndump_stack_lvl+0xd9/0x150\nprint_address_description.constprop.0+0x2c/0x3c0\nkasan_report+0x11d/0x130\ndecode_session6+0x103f/0x1890\n__xfrm_decode_session+0x54/0xb0\nxfrmi_xmit+0x173/0x1ca0\ndev_hard_start_xmit+0x187/0x700\nsch_direct_xmit+0x1a3/0xc30\n__qdisc_run+0x510/0x17a0\n__dev_queue_xmit+0x2215/0x3b10\nneigh_connected_output+0x3c2/0x550\nip6_finish_output2+0x55a/0x1550\nip6_finish_output+0x6b9/0x1270\nip6_output+0x1f1/0x540\nndisc_send_skb+0xa63/0x1890\nndisc_send_rs+0x132/0x6f0\naddrconf_rs_timer+0x3f1/0x870\ncall_timer_fn+0x1a0/0x580\nexpire_timers+0x29b/0x4b0\nrun_timer_softirq+0x326/0x910\n__do_softirq+0x1d4/0x905\nirq_exit_rcu+0xb7/0x120\nsysvec_apic_timer_interrupt+0x97/0xc0\n\u003c/IRQ\u003e\n\u003cTASK\u003e\nasm_sysvec_apic_timer_interrupt+0x1a/0x20\nRIP: 0010:intel_idle_hlt+0x23/0x30\nCode: 1f 84 00 00 00 00 00 f3 0f 1e fa 41 54 41 89 d4 0f 1f 44 00 00 66 90 0f 1f 44 00 00 0f 00 2d c4 9f ab 00 0f 1f 44 00 00 fb f4 \u003cfa\u003e 44 89 e0 41 5c c3 66 0f 1f 44 00 00 f3 0f 1e fa 41 54 41 89 d4\nRSP: 0018:ffffc90000197d78 EFLAGS: 00000246\nRAX: 00000000000a83c3 RBX: ffffe8ffffd09c50 RCX: ffffffff8a22d8e5\nRDX: 0000000000000001 RSI: ffffffff8d3f8080 RDI: ffffe8ffffd09c50\nRBP: ffffffff8d3f8080 R08: 0000000000000001 R09: ffffed1026ba6d9d\nR10: ffff888135d36ceb R11: 0000000000000001 R12: 0000000000000001\nR13: ffffffff8d3f8100 R14: 0000000000000001 R15: 0000000000000000\ncpuidle_enter_state+0xd3/0x6f0\ncpuidle_enter+0x4e/0xa0\ndo_idle+0x2fe/0x3c0\ncpu_startup_entry+0x18/0x20\nstart_secondary+0x200/0x290\nsecondary_startup_64_no_verify+0x167/0x16b\n\u003c/TASK\u003e\nAllocated by task 939:\nkasan_save_stack+0x22/0x40\nkasan_set_track+0x25/0x30\n__kasan_slab_alloc+0x7f/0x90\nkmem_cache_alloc_node+0x1cd/0x410\nkmalloc_reserve+0x165/0x270\n__alloc_skb+0x129/0x330\ninet6_ifa_notify+0x118/0x230\n__ipv6_ifa_notify+0x177/0xbe0\naddrconf_dad_completed+0x133/0xe00\naddrconf_dad_work+0x764/0x1390\nprocess_one_work+0xa32/0x16f0\nworker_thread+0x67d/0x10c0\nkthread+0x344/0x440\nret_from_fork+0x1f/0x30\nThe buggy address belongs to the object at ffff888111145800\nwhich belongs to the cache skbuff_small_head of size 640\nThe buggy address is located 239 bytes inside of\nfreed 640-byte region [ffff888111145800, ffff888111145a80)\n\nAs commit f855691975bb (\"xfrm6: Fix the nexthdr offset in\n_decode_session6.\") showed, xfrm_decode_session was originally intended\nonly for the receive path. IP6CB(skb)-\u003enhoff is not set during\ntransmission. Therefore, set the cb field in the skb to 0 before\nsending packets."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.3,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - Triggering requires locally configuring an xfrm interface and attaching a cb-dirtying qdisc (sfb) via rtnetlink/tc, then emitting IPv6 packets out that device \u2014 all local netlink operations. A remote peer can only trigger it opportunistically on a pre-existing xfrm+fq/sfb deployment, so the vector the attacker can actually establish is local.\nAC:L - The attacker fully controls every precondition: create the xfrm link, attach `sfb` with `rehash 1` to force the slot that leaves a non-zero hash in skb-\u003ecb[14..15], and transmit IPv6 packets at will with unlimited free retries. There is no race to win and no memory layout or victim state outside the attacker\u0027s influence.\nPR:L - Both RTM_NEWLINK and RTM_NEWQDISC gate only on `netlink_net_capable(skb, CAP_NET_ADMIN)`, which resolves to `ns_capable(net-\u003euser_ns, CAP_NET_ADMIN)` and is therefore satisfied by an unprivileged user inside `unshare -Urn`; the required sch_sfb and xfrm_interface modules autoload. No real root in the init namespace is needed.\nUI:N - Once the device is brought up, IPv6 addrconf on the ARPHRD_NONE xfrm interface sends router solicitations by itself (exactly the addrconf_rs_timer path in the KASAN trace), and the attacker can additionally send traffic on demand. No victim action is involved.\nS:U - The out-of-bounds read, the resulting bad policy decision, and any oops all occur within the host kernel\u0027s own security authority. No hypervisor, IOMMU, or sandbox boundary is crossed.\nC:H - `nh[nhoff]` reads a byte at an entirely uncontrolled offset of up to 65535 past a ~640-byte slab object, confirmed by KASAN to land inside freed heap memory, and each packet re-randomizes the offset so an attacker can sweep a 64 KB window of adjacent kernel memory. The recovered byte becomes `flowi6_proto` and steers the xfrm policy/route lookup, providing an observable oracle for that out-of-bounds content.\nI:L - There is no write or corruption primitive \u2014 the stale byte only lands in an on-stack `flowi6` \u2014 but it causes `xfrm_lookup_with_ifid()` to select the wrong policy/SA, so outbound tunnel packets can be emitted under an unintended security association (the \"incorrect policy lookups\" failure f855691975bb was written to prevent). That is a real but limited modification of the security decision.\nA:H - A read up to 64 KB beyond the slab object can hit an unmapped or guarded page, faulting in softirq context for an immediate oops/panic, and on KASAN or hardened kernels it reports and panics outright. Independently, the garbage flow decode makes `xfrm_lookup` fail so `xfrmi_xmit2()` drops every IPv6 packet on the interface, taking the IPsec tunnel down."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-05T09:14:29.679Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/da4cbaa75ed088b6d70db77b9103a27e2359e243"
},
{
"url": "https://git.kernel.org/stable/c/db0e50741f0387f388e9ec824ea7ae8456554d5b"
},
{
"url": "https://git.kernel.org/stable/c/bafa236380816b41b2c4c6970d9067fefa4a6c9e"
},
{
"url": "https://git.kernel.org/stable/c/44b3d40967009304617a7a6486490c1d6c12f899"
},
{
"url": "https://git.kernel.org/stable/c/0d27567fde5be5f0edc2db5c110142b7915b8fa8"
},
{
"url": "https://git.kernel.org/stable/c/86f15300a22656db3fa8c8967defbcd24fac4d37"
},
{
"url": "https://git.kernel.org/stable/c/53223f2ed1ef5c90dad814daaaefea4e68a933c8"
}
],
"title": "xfrm: fix slab-use-after-free in decode_session6",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2023-53500",
"datePublished": "2025-10-01T11:45:51.182Z",
"dateReserved": "2025-10-01T11:39:39.404Z",
"dateUpdated": "2026-10-15T21:41:29.274Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2023-53500",
"date": "2026-11-13",
"epss": "0.00165",
"percentile": "0.05788"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/xfrm/xfrm_interface_core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "da4cbaa75ed088b6d70db77b9103a27e2359e243",
"status": "affected",
"version": "f855691975bb06373a98711e4cfe2c224244b536",
"versionType": "git"
},
{
"lessThan": "db0e50741f0387f388e9ec824ea7ae8456554d5b",
"status": "affected",
"version": "f855691975bb06373a98711e4cfe2c224244b536",
"versionType": "git"
},
{
"lessThan": "bafa236380816b41b2c4c6970d9067fefa4a6c9e",
"status": "affected",
"version": "f855691975bb06373a98711e4cfe2c224244b536",
"versionType": "git"
},
{
"lessThan": "44b3d40967009304617a7a6486490c1d6c12f899",
"status": "affected",
"version": "f855691975bb06373a98711e4cfe2c224244b536",
"versionType": "git"
},
{
"lessThan": "0d27567fde5be5f0edc2db5c110142b7915b8fa8",
"status": "affected",
"version": "f855691975bb06373a98711e4cfe2c224244b536",
"versionType": "git"
},
{
"lessThan": "86f15300a22656db3fa8c8967defbcd24fac4d37",
"status": "affected",
"version": "f855691975bb06373a98711e4cfe2c224244b536",
"versionType": "git"
},
{
"lessThan": "53223f2ed1ef5c90dad814daaaefea4e68a933c8",
"status": "affected",
"version": "f855691975bb06373a98711e4cfe2c224244b536",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/xfrm/xfrm_interface_core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.19"
},
{
"lessThan": "3.19",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "4.19.*",
"status": "unaffected",
"version": "4.19.293",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.4.*",
"status": "unaffected",
"version": "5.4.255",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.192",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.128",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.47",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.4.*",
"status": "unaffected",
"version": "6.4.12",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.5",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "6600AC7B-1E50-44F6-8999-98594E768A52",
"versionEndExcluding": "4.19.293",
"versionStartIncluding": "3.19.1",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "1379E40A-2AC3-484E-929A-7F46B6C3B521",
"versionEndExcluding": "5.4.255",
"versionStartIncluding": "4.20",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "9396FFDC-6A0D-44B7-9368-21B456F6D4AE",
"versionEndExcluding": "5.10.192",
"versionStartIncluding": "5.5",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "1415629F-F97B-4880-BA1E-AF3DBB8EF305",
"versionEndExcluding": "5.15.128",
"versionStartIncluding": "5.11",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "2EEA01B0-0151-4E0F-B140-1A441EEDD717",
"versionEndExcluding": "6.1.47",
"versionStartIncluding": "5.16",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "CF8ECF64-40AE-49AB-8315-4D83F9F56ECF",
"versionEndExcluding": "6.4.12",
"versionStartIncluding": "6.2",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:3.19:-:*:*:*:*:*:*",
"matchCriteriaId": "8C54596F-5461-44C4-91FB-7453BE905748",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:3.19:rc7:*:*:*:*:*:*",
"matchCriteriaId": "5843CB48-122D-496D-B66D-35296BC0EFB1",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.5:rc1:*:*:*:*:*:*",
"matchCriteriaId": "0B3E6E4D-E24E-4630-B00C-8C9901C597B0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.5:rc2:*:*:*:*:*:*",
"matchCriteriaId": "E4A01A71-0F09-4DB2-A02F-7EFFBE27C98D",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.5:rc3:*:*:*:*:*:*",
"matchCriteriaId": "F5608371-157A-4318-8A2E-4104C3467EA1",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.5:rc4:*:*:*:*:*:*",
"matchCriteriaId": "2226A776-DF8C-49E0-A030-0A7853BB018A",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.5:rc5:*:*:*:*:*:*",
"matchCriteriaId": "6F15C659-DF06-455A-9765-0E6DE920F29A",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.5:rc6:*:*:*:*:*:*",
"matchCriteriaId": "5B1C14ED-ABC4-41D3-8D9C-D38C6A65B4DE",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: fix slab-use-after-free in decode_session6\n\nWhen the xfrm device is set to the qdisc of the sfb type, the cb field\nof the sent skb may be modified during enqueuing. Then,\nslab-use-after-free may occur when the xfrm device sends IPv6 packets.\n\nThe stack information is as follows:\nBUG: KASAN: slab-use-after-free in decode_session6+0x103f/0x1890\nRead of size 1 at addr ffff8881111458ef by task swapper/3/0\nCPU: 3 PID: 0 Comm: swapper/3 Not tainted 6.4.0-next-20230707 #409\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014\nCall Trace:\n\u003cIRQ\u003e\ndump_stack_lvl+0xd9/0x150\nprint_address_description.constprop.0+0x2c/0x3c0\nkasan_report+0x11d/0x130\ndecode_session6+0x103f/0x1890\n__xfrm_decode_session+0x54/0xb0\nxfrmi_xmit+0x173/0x1ca0\ndev_hard_start_xmit+0x187/0x700\nsch_direct_xmit+0x1a3/0xc30\n__qdisc_run+0x510/0x17a0\n__dev_queue_xmit+0x2215/0x3b10\nneigh_connected_output+0x3c2/0x550\nip6_finish_output2+0x55a/0x1550\nip6_finish_output+0x6b9/0x1270\nip6_output+0x1f1/0x540\nndisc_send_skb+0xa63/0x1890\nndisc_send_rs+0x132/0x6f0\naddrconf_rs_timer+0x3f1/0x870\ncall_timer_fn+0x1a0/0x580\nexpire_timers+0x29b/0x4b0\nrun_timer_softirq+0x326/0x910\n__do_softirq+0x1d4/0x905\nirq_exit_rcu+0xb7/0x120\nsysvec_apic_timer_interrupt+0x97/0xc0\n\u003c/IRQ\u003e\n\u003cTASK\u003e\nasm_sysvec_apic_timer_interrupt+0x1a/0x20\nRIP: 0010:intel_idle_hlt+0x23/0x30\nCode: 1f 84 00 00 00 00 00 f3 0f 1e fa 41 54 41 89 d4 0f 1f 44 00 00 66 90 0f 1f 44 00 00 0f 00 2d c4 9f ab 00 0f 1f 44 00 00 fb f4 \u003cfa\u003e 44 89 e0 41 5c c3 66 0f 1f 44 00 00 f3 0f 1e fa 41 54 41 89 d4\nRSP: 0018:ffffc90000197d78 EFLAGS: 00000246\nRAX: 00000000000a83c3 RBX: ffffe8ffffd09c50 RCX: ffffffff8a22d8e5\nRDX: 0000000000000001 RSI: ffffffff8d3f8080 RDI: ffffe8ffffd09c50\nRBP: ffffffff8d3f8080 R08: 0000000000000001 R09: ffffed1026ba6d9d\nR10: ffff888135d36ceb R11: 0000000000000001 R12: 0000000000000001\nR13: ffffffff8d3f8100 R14: 0000000000000001 R15: 0000000000000000\ncpuidle_enter_state+0xd3/0x6f0\ncpuidle_enter+0x4e/0xa0\ndo_idle+0x2fe/0x3c0\ncpu_startup_entry+0x18/0x20\nstart_secondary+0x200/0x290\nsecondary_startup_64_no_verify+0x167/0x16b\n\u003c/TASK\u003e\nAllocated by task 939:\nkasan_save_stack+0x22/0x40\nkasan_set_track+0x25/0x30\n__kasan_slab_alloc+0x7f/0x90\nkmem_cache_alloc_node+0x1cd/0x410\nkmalloc_reserve+0x165/0x270\n__alloc_skb+0x129/0x330\ninet6_ifa_notify+0x118/0x230\n__ipv6_ifa_notify+0x177/0xbe0\naddrconf_dad_completed+0x133/0xe00\naddrconf_dad_work+0x764/0x1390\nprocess_one_work+0xa32/0x16f0\nworker_thread+0x67d/0x10c0\nkthread+0x344/0x440\nret_from_fork+0x1f/0x30\nThe buggy address belongs to the object at ffff888111145800\nwhich belongs to the cache skbuff_small_head of size 640\nThe buggy address is located 239 bytes inside of\nfreed 640-byte region [ffff888111145800, ffff888111145a80)\n\nAs commit f855691975bb (\"xfrm6: Fix the nexthdr offset in\n_decode_session6.\") showed, xfrm_decode_session was originally intended\nonly for the receive path. IP6CB(skb)-\u003enhoff is not set during\ntransmission. Therefore, set the cb field in the skb to 0 before\nsending packets."
}
],
"id": "CVE-2023-53500",
"lastModified": "2026-10-15T22:17:41.187",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.3,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "LOW",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 5.5,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
},
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9,
"source": "nvd@nist.gov",
"type": "Primary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2023-53500",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-10-15T21:35:03.965341Z",
"version": "2.0.3"
}
}
]
},
"published": "2025-10-01T12:15:53.490",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/0d27567fde5be5f0edc2db5c110142b7915b8fa8"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/44b3d40967009304617a7a6486490c1d6c12f899"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/53223f2ed1ef5c90dad814daaaefea4e68a933c8"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/86f15300a22656db3fa8c8967defbcd24fac4d37"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/bafa236380816b41b2c4c6970d9067fefa4a6c9e"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/da4cbaa75ed088b6d70db77b9103a27e2359e243"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/db0e50741f0387f388e9ec824ea7ae8456554d5b"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Modified",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-416"
}
],
"source": "nvd@nist.gov",
"type": "Primary"
}
]
}
},
"redhat_vex": {
"aggregate_severity": "Moderate",
"current_release_date": "2026-11-09T17:28:40+00:00",
"cve": "CVE-2023-53500",
"id": "CVE-2023-53500",
"initial_release_date": "2023-01-01T00:00:00+00:00",
"product_status:known_affected": "157",
"product_status:known_not_affected": "43",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: xfrm: fix slab-use-after-free in decode_session6",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2023/cve-2023-53500.json",
"version": "3"
},
"vulnrichment": {
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2023-53500",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-10-15T21:35:03.965341Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-10-15T21:35:05.343Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/xfrm/xfrm_interface_core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "da4cbaa75ed088b6d70db77b9103a27e2359e243",
"status": "affected",
"version": "f855691975bb06373a98711e4cfe2c224244b536",
"versionType": "git"
},
{
"lessThan": "db0e50741f0387f388e9ec824ea7ae8456554d5b",
"status": "affected",
"version": "f855691975bb06373a98711e4cfe2c224244b536",
"versionType": "git"
},
{
"lessThan": "bafa236380816b41b2c4c6970d9067fefa4a6c9e",
"status": "affected",
"version": "f855691975bb06373a98711e4cfe2c224244b536",
"versionType": "git"
},
{
"lessThan": "44b3d40967009304617a7a6486490c1d6c12f899",
"status": "affected",
"version": "f855691975bb06373a98711e4cfe2c224244b536",
"versionType": "git"
},
{
"lessThan": "0d27567fde5be5f0edc2db5c110142b7915b8fa8",
"status": "affected",
"version": "f855691975bb06373a98711e4cfe2c224244b536",
"versionType": "git"
},
{
"lessThan": "86f15300a22656db3fa8c8967defbcd24fac4d37",
"status": "affected",
"version": "f855691975bb06373a98711e4cfe2c224244b536",
"versionType": "git"
},
{
"lessThan": "53223f2ed1ef5c90dad814daaaefea4e68a933c8",
"status": "affected",
"version": "f855691975bb06373a98711e4cfe2c224244b536",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/xfrm/xfrm_interface_core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.19"
},
{
"lessThan": "3.19",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "4.19.*",
"status": "unaffected",
"version": "4.19.293",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.4.*",
"status": "unaffected",
"version": "5.4.255",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.192",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.128",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.47",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.4.*",
"status": "unaffected",
"version": "6.4.12",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.5",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "4.19.293",
"versionStartIncluding": "3.19",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.4.255",
"versionStartIncluding": "3.19",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.10.192",
"versionStartIncluding": "3.19",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15.128",
"versionStartIncluding": "3.19",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.47",
"versionStartIncluding": "3.19",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.4.12",
"versionStartIncluding": "3.19",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.5",
"versionStartIncluding": "3.19",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: fix slab-use-after-free in decode_session6\n\nWhen the xfrm device is set to the qdisc of the sfb type, the cb field\nof the sent skb may be modified during enqueuing. Then,\nslab-use-after-free may occur when the xfrm device sends IPv6 packets.\n\nThe stack information is as follows:\nBUG: KASAN: slab-use-after-free in decode_session6+0x103f/0x1890\nRead of size 1 at addr ffff8881111458ef by task swapper/3/0\nCPU: 3 PID: 0 Comm: swapper/3 Not tainted 6.4.0-next-20230707 #409\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014\nCall Trace:\n\u003cIRQ\u003e\ndump_stack_lvl+0xd9/0x150\nprint_address_description.constprop.0+0x2c/0x3c0\nkasan_report+0x11d/0x130\ndecode_session6+0x103f/0x1890\n__xfrm_decode_session+0x54/0xb0\nxfrmi_xmit+0x173/0x1ca0\ndev_hard_start_xmit+0x187/0x700\nsch_direct_xmit+0x1a3/0xc30\n__qdisc_run+0x510/0x17a0\n__dev_queue_xmit+0x2215/0x3b10\nneigh_connected_output+0x3c2/0x550\nip6_finish_output2+0x55a/0x1550\nip6_finish_output+0x6b9/0x1270\nip6_output+0x1f1/0x540\nndisc_send_skb+0xa63/0x1890\nndisc_send_rs+0x132/0x6f0\naddrconf_rs_timer+0x3f1/0x870\ncall_timer_fn+0x1a0/0x580\nexpire_timers+0x29b/0x4b0\nrun_timer_softirq+0x326/0x910\n__do_softirq+0x1d4/0x905\nirq_exit_rcu+0xb7/0x120\nsysvec_apic_timer_interrupt+0x97/0xc0\n\u003c/IRQ\u003e\n\u003cTASK\u003e\nasm_sysvec_apic_timer_interrupt+0x1a/0x20\nRIP: 0010:intel_idle_hlt+0x23/0x30\nCode: 1f 84 00 00 00 00 00 f3 0f 1e fa 41 54 41 89 d4 0f 1f 44 00 00 66 90 0f 1f 44 00 00 0f 00 2d c4 9f ab 00 0f 1f 44 00 00 fb f4 \u003cfa\u003e 44 89 e0 41 5c c3 66 0f 1f 44 00 00 f3 0f 1e fa 41 54 41 89 d4\nRSP: 0018:ffffc90000197d78 EFLAGS: 00000246\nRAX: 00000000000a83c3 RBX: ffffe8ffffd09c50 RCX: ffffffff8a22d8e5\nRDX: 0000000000000001 RSI: ffffffff8d3f8080 RDI: ffffe8ffffd09c50\nRBP: ffffffff8d3f8080 R08: 0000000000000001 R09: ffffed1026ba6d9d\nR10: ffff888135d36ceb R11: 0000000000000001 R12: 0000000000000001\nR13: ffffffff8d3f8100 R14: 0000000000000001 R15: 0000000000000000\ncpuidle_enter_state+0xd3/0x6f0\ncpuidle_enter+0x4e/0xa0\ndo_idle+0x2fe/0x3c0\ncpu_startup_entry+0x18/0x20\nstart_secondary+0x200/0x290\nsecondary_startup_64_no_verify+0x167/0x16b\n\u003c/TASK\u003e\nAllocated by task 939:\nkasan_save_stack+0x22/0x40\nkasan_set_track+0x25/0x30\n__kasan_slab_alloc+0x7f/0x90\nkmem_cache_alloc_node+0x1cd/0x410\nkmalloc_reserve+0x165/0x270\n__alloc_skb+0x129/0x330\ninet6_ifa_notify+0x118/0x230\n__ipv6_ifa_notify+0x177/0xbe0\naddrconf_dad_completed+0x133/0xe00\naddrconf_dad_work+0x764/0x1390\nprocess_one_work+0xa32/0x16f0\nworker_thread+0x67d/0x10c0\nkthread+0x344/0x440\nret_from_fork+0x1f/0x30\nThe buggy address belongs to the object at ffff888111145800\nwhich belongs to the cache skbuff_small_head of size 640\nThe buggy address is located 239 bytes inside of\nfreed 640-byte region [ffff888111145800, ffff888111145a80)\n\nAs commit f855691975bb (\"xfrm6: Fix the nexthdr offset in\n_decode_session6.\") showed, xfrm_decode_session was originally intended\nonly for the receive path. IP6CB(skb)-\u003enhoff is not set during\ntransmission. Therefore, set the cb field in the skb to 0 before\nsending packets."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.3,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - Triggering requires locally configuring an xfrm interface and attaching a cb-dirtying qdisc (sfb) via rtnetlink/tc, then emitting IPv6 packets out that device \u2014 all local netlink operations. A remote peer can only trigger it opportunistically on a pre-existing xfrm+fq/sfb deployment, so the vector the attacker can actually establish is local.\nAC:L - The attacker fully controls every precondition: create the xfrm link, attach `sfb` with `rehash 1` to force the slot that leaves a non-zero hash in skb-\u003ecb[14..15], and transmit IPv6 packets at will with unlimited free retries. There is no race to win and no memory layout or victim state outside the attacker\u0027s influence.\nPR:L - Both RTM_NEWLINK and RTM_NEWQDISC gate only on `netlink_net_capable(skb, CAP_NET_ADMIN)`, which resolves to `ns_capable(net-\u003euser_ns, CAP_NET_ADMIN)` and is therefore satisfied by an unprivileged user inside `unshare -Urn`; the required sch_sfb and xfrm_interface modules autoload. No real root in the init namespace is needed.\nUI:N - Once the device is brought up, IPv6 addrconf on the ARPHRD_NONE xfrm interface sends router solicitations by itself (exactly the addrconf_rs_timer path in the KASAN trace), and the attacker can additionally send traffic on demand. No victim action is involved.\nS:U - The out-of-bounds read, the resulting bad policy decision, and any oops all occur within the host kernel\u0027s own security authority. No hypervisor, IOMMU, or sandbox boundary is crossed.\nC:H - `nh[nhoff]` reads a byte at an entirely uncontrolled offset of up to 65535 past a ~640-byte slab object, confirmed by KASAN to land inside freed heap memory, and each packet re-randomizes the offset so an attacker can sweep a 64 KB window of adjacent kernel memory. The recovered byte becomes `flowi6_proto` and steers the xfrm policy/route lookup, providing an observable oracle for that out-of-bounds content.\nI:L - There is no write or corruption primitive \u2014 the stale byte only lands in an on-stack `flowi6` \u2014 but it causes `xfrm_lookup_with_ifid()` to select the wrong policy/SA, so outbound tunnel packets can be emitted under an unintended security association (the \"incorrect policy lookups\" failure f855691975bb was written to prevent). That is a real but limited modification of the security decision.\nA:H - A read up to 64 KB beyond the slab object can hit an unmapped or guarded page, faulting in softirq context for an immediate oops/panic, and on KASAN or hardened kernels it reports and panics outright. Independently, the garbage flow decode makes `xfrm_lookup` fail so `xfrmi_xmit2()` drops every IPv6 packet on the interface, taking the IPsec tunnel down."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-05T09:14:29.679Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/da4cbaa75ed088b6d70db77b9103a27e2359e243"
},
{
"url": "https://git.kernel.org/stable/c/db0e50741f0387f388e9ec824ea7ae8456554d5b"
},
{
"url": "https://git.kernel.org/stable/c/bafa236380816b41b2c4c6970d9067fefa4a6c9e"
},
{
"url": "https://git.kernel.org/stable/c/44b3d40967009304617a7a6486490c1d6c12f899"
},
{
"url": "https://git.kernel.org/stable/c/0d27567fde5be5f0edc2db5c110142b7915b8fa8"
},
{
"url": "https://git.kernel.org/stable/c/86f15300a22656db3fa8c8967defbcd24fac4d37"
},
{
"url": "https://git.kernel.org/stable/c/53223f2ed1ef5c90dad814daaaefea4e68a933c8"
}
],
"title": "xfrm: fix slab-use-after-free in decode_session6",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2023-53500",
"datePublished": "2025-10-01T11:45:51.182Z",
"dateReserved": "2025-10-01T11:39:39.404Z",
"dateUpdated": "2026-10-15T21:41:29.274Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
How durations are calculated
Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.
Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.
Loading timeline…
Loading…
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.