FKIE_CVE-2026-74569
Vulnerability from fkie_nvd - Published: 2026-08-15 13:18 - Updated: 2026-08-19 17:21
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_conntrack_sip: widen NAT rewrite delta to s32 in sip_help_tcp()
sip_help_tcp() stores the size change of each NAT-rewritten SIP message
in s16 diff and accumulates it in s16 tdiff, but a single message can
grow by more than S16_MAX while the packet stays under the 65535
enlarge_skb() limit: nf_nat_sip() rewrites every matching URI, and a long
Contact list expands the message by tens of kilobytes. diff then wraps,
and "datalen = datalen + diff - msglen" yields a huge unsigned datalen,
so the next iteration's ct_sip_get_header() reads past the linearized skb
tail.
Widen diff, tdiff and the seq_adjust hook to s32. Both are bounded by the
65535 byte packet limit, and the seqadj core is already s32
(nf_ct_seqadj_set() takes s32), so no previously accepted input is
rejected.
BUG: KASAN: use-after-free in ct_sip_get_header (net/netfilter/nf_conntrack_sip.c:464)
Read of size 1 at addr ffff888010800000 by task ksoftirqd/1/25
ct_sip_get_header (net/netfilter/nf_conntrack_sip.c:464)
sip_help_tcp (net/netfilter/nf_conntrack_sip.c:1694)
nf_confirm (net/netfilter/nf_conntrack_proto.c:183)
nf_hook_slow (net/netfilter/core.c:619)
ip6_output (net/ipv6/ip6_output.c:246)
ip6_forward (net/ipv6/ip6_output.c:690)
ipv6_rcv (net/ipv6/ip6_input.c:351)
__netif_receive_skb_one_core (net/core/dev.c:6212)
process_backlog (net/core/dev.c:6676)
__napi_poll (net/core/dev.c:7735)
net_rx_action (net/core/dev.c:7955)
handle_softirqs (kernel/softirq.c:622)
run_ksoftirqd (kernel/softirq.c:1076)
...
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"include/linux/netfilter/nf_conntrack_sip.h",
"net/netfilter/nf_conntrack_sip.c",
"net/netfilter/nf_nat_sip.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "ed1f9be6dc8e2e280b8725e44ccdc6e0cd38640d",
"status": "affected",
"version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
"versionType": "git"
},
{
"lessThan": "1b0843f9e9b9b0b9b4b70d143b67e58163c85b2c",
"status": "affected",
"version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
"versionType": "git"
},
{
"lessThan": "32d4abc8923b0d4046fd63ad6e4917872e44eb6d",
"status": "affected",
"version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
"versionType": "git"
},
{
"lessThan": "63eea41759fd682229c14e0a2205802b46d106f3",
"status": "affected",
"version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
"versionType": "git"
},
{
"lessThan": "c97621a110e386b2dd69e276eb699e1d3cec581d",
"status": "affected",
"version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
"versionType": "git"
},
{
"lessThan": "f74554e67ccf04d1fa71069e8c9afa2717e40716",
"status": "affected",
"version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
"versionType": "git"
},
{
"lessThan": "ef5e2c6555d2bb52dfe0e4053a8c6193f9d83b64",
"status": "affected",
"version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
"versionType": "git"
},
{
"lessThan": "db3d0e0e5d4bc5ab4fe445b9f413d1b486508ca5",
"status": "affected",
"version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"include/linux/netfilter/nf_conntrack_sip.h",
"net/netfilter/nf_conntrack_sip.c",
"net/netfilter/nf_nat_sip.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.34"
},
{
"lessThan": "2.6.34",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.265",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.216",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.183",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.151",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.103",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.44",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.8",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack_sip: widen NAT rewrite delta to s32 in sip_help_tcp()\n\nsip_help_tcp() stores the size change of each NAT-rewritten SIP message\nin s16 diff and accumulates it in s16 tdiff, but a single message can\ngrow by more than S16_MAX while the packet stays under the 65535\nenlarge_skb() limit: nf_nat_sip() rewrites every matching URI, and a long\nContact list expands the message by tens of kilobytes. diff then wraps,\nand \"datalen = datalen + diff - msglen\" yields a huge unsigned datalen,\nso the next iteration\u0027s ct_sip_get_header() reads past the linearized skb\ntail.\n\nWiden diff, tdiff and the seq_adjust hook to s32. Both are bounded by the\n65535 byte packet limit, and the seqadj core is already s32\n(nf_ct_seqadj_set() takes s32), so no previously accepted input is\nrejected.\n\n BUG: KASAN: use-after-free in ct_sip_get_header (net/netfilter/nf_conntrack_sip.c:464)\n Read of size 1 at addr ffff888010800000 by task ksoftirqd/1/25\n ct_sip_get_header (net/netfilter/nf_conntrack_sip.c:464)\n sip_help_tcp (net/netfilter/nf_conntrack_sip.c:1694)\n nf_confirm (net/netfilter/nf_conntrack_proto.c:183)\n nf_hook_slow (net/netfilter/core.c:619)\n ip6_output (net/ipv6/ip6_output.c:246)\n ip6_forward (net/ipv6/ip6_output.c:690)\n ipv6_rcv (net/ipv6/ip6_input.c:351)\n __netif_receive_skb_one_core (net/core/dev.c:6212)\n process_backlog (net/core/dev.c:6676)\n __napi_poll (net/core/dev.c:7735)\n net_rx_action (net/core/dev.c:7955)\n handle_softirqs (kernel/softirq.c:622)\n run_ksoftirqd (kernel/softirq.c:1076)\n ..."
}
],
"id": "CVE-2026-74569",
"lastModified": "2026-08-19T17:21:11.713",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 9.8,
"baseSeverity": "CRITICAL",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 3.9,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-08-15T13:18:02.517",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/1b0843f9e9b9b0b9b4b70d143b67e58163c85b2c"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/32d4abc8923b0d4046fd63ad6e4917872e44eb6d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/63eea41759fd682229c14e0a2205802b46d106f3"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/c97621a110e386b2dd69e276eb699e1d3cec581d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/db3d0e0e5d4bc5ab4fe445b9f413d1b486508ca5"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/ed1f9be6dc8e2e280b8725e44ccdc6e0cd38640d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/ef5e2c6555d2bb52dfe0e4053a8c6193f9d83b64"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/f74554e67ccf04d1fa71069e8c9afa2717e40716"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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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.
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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.
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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.
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