Vulnerability-Lookup

GHSA-CP65-XQ47-M66J

Vulnerability from github – Published: 2026-03-25 12:30 – Updated: 2026-03-25 12:30

Details

In the Linux kernel, the following vulnerability has been resolved:

mptcp: pm: in-kernel: always mark signal+subflow endp as used

Syzkaller managed to find a combination of actions that was generating this warning:

msk->pm.local_addr_used == 0 WARNING: net/mptcp/pm_kernel.c:1071 at __mark_subflow_endp_available net/mptcp/pm_kernel.c:1071 [inline], CPU#1: syz.2.17/961 WARNING: net/mptcp/pm_kernel.c:1071 at mptcp_nl_remove_subflow_and_signal_addr net/mptcp/pm_kernel.c:1103 [inline], CPU#1: syz.2.17/961 WARNING: net/mptcp/pm_kernel.c:1071 at mptcp_pm_nl_del_addr_doit+0x81d/0x8f0 net/mptcp/pm_kernel.c:1210, CPU#1: syz.2.17/961 Modules linked in: CPU: 1 UID: 0 PID: 961 Comm: syz.2.17 Not tainted 6.19.0-08368-gfafda3b4b06b #22 PREEMPT(full) Hardware name: QEMU Ubuntu 25.10 PC v2 (i440FX + PIIX, + 10.1 machine, 1996), BIOS 1.17.0-debian-1.17.0-1build1 04/01/2014 RIP: 0010:__mark_subflow_endp_available net/mptcp/pm_kernel.c:1071 [inline] RIP: 0010:mptcp_nl_remove_subflow_and_signal_addr net/mptcp/pm_kernel.c:1103 [inline] RIP: 0010:mptcp_pm_nl_del_addr_doit+0x81d/0x8f0 net/mptcp/pm_kernel.c:1210 Code: 89 c5 e8 46 30 6f fe e9 21 fd ff ff 49 83 ed 80 e8 38 30 6f fe 4c 89 ef be 03 00 00 00 e8 db 49 df fe eb ac e8 24 30 6f fe 90 <0f> 0b 90 e9 1d ff ff ff e8 16 30 6f fe eb 05 e8 0f 30 6f fe e8 9a RSP: 0018:ffffc90001663880 EFLAGS: 00010293 RAX: ffffffff82de1a6c RBX: 0000000000000000 RCX: ffff88800722b500 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff8880158b22d0 R08: 0000000000010425 R09: ffffffffffffffff R10: ffffffff82de18ba R11: 0000000000000000 R12: ffff88800641a640 R13: ffff8880158b1880 R14: ffff88801ec3c900 R15: ffff88800641a650 FS: 00005555722c3500(0000) GS:ffff8880f909d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f66346e0f60 CR3: 000000001607c000 CR4: 0000000000350ef0 Call Trace: genl_family_rcv_msg_doit+0x117/0x180 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x3a8/0x3f0 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x16d/0x240 net/netlink/af_netlink.c:2550 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x3e9/0x4c0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x4aa/0x5b0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0xc9/0xf0 net/socket.c:742 _syssendmsg+0x272/0x3b0 net/socket.c:2592 _sys_sendmsg+0x2de/0x320 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x110/0x1a0 net/socket.c:2681 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x143/0x440 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f66346f826d Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc83d8bdc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f6634985fa0 RCX: 00007f66346f826d RDX: 00000000040000b0 RSI: 0000200000000740 RDI: 0000000000000007 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6634985fa8 R13: 00007f6634985fac R14: 0000000000000000 R15: 0000000000001770

The actions that caused that seem to be:

Set the MPTCP subflows limit to 0
Create an MPTCP endpoint with both the 'signal' and 'subflow' flags
Create a new MPTCP connection from a different address: an ADD_ADDR linked to the MPTCP endpoint will be sent ('signal' flag), but no subflows is initiated ('subflow' flag)
Remove the MPTCP endpoint

---truncated---

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JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-23321"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-03-25T11:16:28Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: pm: in-kernel: always mark signal+subflow endp as used\n\nSyzkaller managed to find a combination of actions that was generating\nthis warning:\n\n  msk-\u003epm.local_addr_used == 0\n  WARNING: net/mptcp/pm_kernel.c:1071 at __mark_subflow_endp_available net/mptcp/pm_kernel.c:1071 [inline], CPU#1: syz.2.17/961\n  WARNING: net/mptcp/pm_kernel.c:1071 at mptcp_nl_remove_subflow_and_signal_addr net/mptcp/pm_kernel.c:1103 [inline], CPU#1: syz.2.17/961\n  WARNING: net/mptcp/pm_kernel.c:1071 at mptcp_pm_nl_del_addr_doit+0x81d/0x8f0 net/mptcp/pm_kernel.c:1210, CPU#1: syz.2.17/961\n  Modules linked in:\n  CPU: 1 UID: 0 PID: 961 Comm: syz.2.17 Not tainted 6.19.0-08368-gfafda3b4b06b #22 PREEMPT(full)\n  Hardware name: QEMU Ubuntu 25.10 PC v2 (i440FX + PIIX, + 10.1 machine, 1996), BIOS 1.17.0-debian-1.17.0-1build1 04/01/2014\n  RIP: 0010:__mark_subflow_endp_available net/mptcp/pm_kernel.c:1071 [inline]\n  RIP: 0010:mptcp_nl_remove_subflow_and_signal_addr net/mptcp/pm_kernel.c:1103 [inline]\n  RIP: 0010:mptcp_pm_nl_del_addr_doit+0x81d/0x8f0 net/mptcp/pm_kernel.c:1210\n  Code: 89 c5 e8 46 30 6f fe e9 21 fd ff ff 49 83 ed 80 e8 38 30 6f fe 4c 89 ef be 03 00 00 00 e8 db 49 df fe eb ac e8 24 30 6f fe 90 \u003c0f\u003e 0b 90 e9 1d ff ff ff e8 16 30 6f fe eb 05 e8 0f 30 6f fe e8 9a\n  RSP: 0018:ffffc90001663880 EFLAGS: 00010293\n  RAX: ffffffff82de1a6c RBX: 0000000000000000 RCX: ffff88800722b500\n  RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000\n  RBP: ffff8880158b22d0 R08: 0000000000010425 R09: ffffffffffffffff\n  R10: ffffffff82de18ba R11: 0000000000000000 R12: ffff88800641a640\n  R13: ffff8880158b1880 R14: ffff88801ec3c900 R15: ffff88800641a650\n  FS:  00005555722c3500(0000) GS:ffff8880f909d000(0000) knlGS:0000000000000000\n  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n  CR2: 00007f66346e0f60 CR3: 000000001607c000 CR4: 0000000000350ef0\n  Call Trace:\n   \u003cTASK\u003e\n   genl_family_rcv_msg_doit+0x117/0x180 net/netlink/genetlink.c:1115\n   genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]\n   genl_rcv_msg+0x3a8/0x3f0 net/netlink/genetlink.c:1210\n   netlink_rcv_skb+0x16d/0x240 net/netlink/af_netlink.c:2550\n   genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219\n   netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]\n   netlink_unicast+0x3e9/0x4c0 net/netlink/af_netlink.c:1344\n   netlink_sendmsg+0x4aa/0x5b0 net/netlink/af_netlink.c:1894\n   sock_sendmsg_nosec net/socket.c:727 [inline]\n   __sock_sendmsg+0xc9/0xf0 net/socket.c:742\n   ____sys_sendmsg+0x272/0x3b0 net/socket.c:2592\n   ___sys_sendmsg+0x2de/0x320 net/socket.c:2646\n   __sys_sendmsg net/socket.c:2678 [inline]\n   __do_sys_sendmsg net/socket.c:2683 [inline]\n   __se_sys_sendmsg net/socket.c:2681 [inline]\n   __x64_sys_sendmsg+0x110/0x1a0 net/socket.c:2681\n   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n   do_syscall_64+0x143/0x440 arch/x86/entry/syscall_64.c:94\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n  RIP: 0033:0x7f66346f826d\n  Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 \u003c48\u003e 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48\n  RSP: 002b:00007ffc83d8bdc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e\n  RAX: ffffffffffffffda RBX: 00007f6634985fa0 RCX: 00007f66346f826d\n  RDX: 00000000040000b0 RSI: 0000200000000740 RDI: 0000000000000007\n  RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000\n  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6634985fa8\n  R13: 00007f6634985fac R14: 0000000000000000 R15: 0000000000001770\n   \u003c/TASK\u003e\n\nThe actions that caused that seem to be:\n\n - Set the MPTCP subflows limit to 0\n - Create an MPTCP endpoint with both the \u0027signal\u0027 and \u0027subflow\u0027 flags\n - Create a new MPTCP connection from a different address: an ADD_ADDR\n   linked to the MPTCP endpoint will be sent (\u0027signal\u0027 flag), but no\n   subflows is initiated (\u0027subflow\u0027 flag)\n - Remove the MPTCP endpoint\n\n---truncated---",
  "id": "GHSA-cp65-xq47-m66j",
  "modified": "2026-03-25T12:30:22Z",
  "published": "2026-03-25T12:30:22Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23321"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/05799c2f1ca5eb13d65764dda688d02021b65e06"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/198824ccfa64ffebd918bf99c939bd8170a4a4d8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/579a752464a64cb5f9139102f0e6b90a1f595ceb"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/67f34ab318807989b57dfdb0f79e2d4e57018290"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a64aa7db39392add5be09dffaedbf1f0ce5554df"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c5c877e140e5f46023a74a51e577ce5edd0a4be7"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-23321 (GCVE-0-2026-23321)

Vulnerability from cvelistv5 – Published: 2026-03-25 10:27 – Updated: 2026-03-25 10:27

Title

mptcp: pm: in-kernel: always mark signal+subflow endp as used

Summary

In the Linux kernel, the following vulnerability has been resolved: mptcp: pm: in-kernel: always mark signal+subflow endp as used Syzkaller managed to find a combination of actions that was generating this warning: msk->pm.local_addr_used == 0 WARNING: net/mptcp/pm_kernel.c:1071 at __mark_subflow_endp_available net/mptcp/pm_kernel.c:1071 [inline], CPU#1: syz.2.17/961 WARNING: net/mptcp/pm_kernel.c:1071 at mptcp_nl_remove_subflow_and_signal_addr net/mptcp/pm_kernel.c:1103 [inline], CPU#1: syz.2.17/961 WARNING: net/mptcp/pm_kernel.c:1071 at mptcp_pm_nl_del_addr_doit+0x81d/0x8f0 net/mptcp/pm_kernel.c:1210, CPU#1: syz.2.17/961 Modules linked in: CPU: 1 UID: 0 PID: 961 Comm: syz.2.17 Not tainted 6.19.0-08368-gfafda3b4b06b #22 PREEMPT(full) Hardware name: QEMU Ubuntu 25.10 PC v2 (i440FX + PIIX, + 10.1 machine, 1996), BIOS 1.17.0-debian-1.17.0-1build1 04/01/2014 RIP: 0010:__mark_subflow_endp_available net/mptcp/pm_kernel.c:1071 [inline] RIP: 0010:mptcp_nl_remove_subflow_and_signal_addr net/mptcp/pm_kernel.c:1103 [inline] RIP: 0010:mptcp_pm_nl_del_addr_doit+0x81d/0x8f0 net/mptcp/pm_kernel.c:1210 Code: 89 c5 e8 46 30 6f fe e9 21 fd ff ff 49 83 ed 80 e8 38 30 6f fe 4c 89 ef be 03 00 00 00 e8 db 49 df fe eb ac e8 24 30 6f fe 90 <0f> 0b 90 e9 1d ff ff ff e8 16 30 6f fe eb 05 e8 0f 30 6f fe e8 9a RSP: 0018:ffffc90001663880 EFLAGS: 00010293 RAX: ffffffff82de1a6c RBX: 0000000000000000 RCX: ffff88800722b500 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff8880158b22d0 R08: 0000000000010425 R09: ffffffffffffffff R10: ffffffff82de18ba R11: 0000000000000000 R12: ffff88800641a640 R13: ffff8880158b1880 R14: ffff88801ec3c900 R15: ffff88800641a650 FS: 00005555722c3500(0000) GS:ffff8880f909d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f66346e0f60 CR3: 000000001607c000 CR4: 0000000000350ef0 Call Trace: <TASK> genl_family_rcv_msg_doit+0x117/0x180 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x3a8/0x3f0 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x16d/0x240 net/netlink/af_netlink.c:2550 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x3e9/0x4c0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x4aa/0x5b0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0xc9/0xf0 net/socket.c:742 ____sys_sendmsg+0x272/0x3b0 net/socket.c:2592 ___sys_sendmsg+0x2de/0x320 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x110/0x1a0 net/socket.c:2681 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x143/0x440 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f66346f826d Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc83d8bdc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f6634985fa0 RCX: 00007f66346f826d RDX: 00000000040000b0 RSI: 0000200000000740 RDI: 0000000000000007 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6634985fa8 R13: 00007f6634985fac R14: 0000000000000000 R15: 0000000000001770 </TASK> The actions that caused that seem to be: - Set the MPTCP subflows limit to 0 - Create an MPTCP endpoint with both the 'signal' and 'subflow' flags - Create a new MPTCP connection from a different address: an ADD_ADDR linked to the MPTCP endpoint will be sent ('signal' flag), but no subflows is initiated ('subflow' flag) - Remove the MPTCP endpoint ---truncated---

Severity ?

No CVSS data available.

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/c5c877e140e5f4602…
	https://git.kernel.org/stable/c/05799c2f1ca5eb13d…
	https://git.kernel.org/stable/c/67f34ab318807989b…
	https://git.kernel.org/stable/c/a64aa7db39392add5…
	https://git.kernel.org/stable/c/198824ccfa64ffebd…
	https://git.kernel.org/stable/c/579a752464a64cb5f…

Impacted products

Vendor

Product

Version

Linux

Affected: d93cf38fad9f66397093432b8917971a92ee0146 , < c5c877e140e5f46023a74a51e577ce5edd0a4be7 (git)
Affected: 64815ba15880ce5f99df075fa4104fef170ac7e5 , < 05799c2f1ca5eb13d65764dda688d02021b65e06 (git)
Affected: 85df533a787bf07bf4367ce2a02b822ff1fba1a3 , < 67f34ab318807989b57dfdb0f79e2d4e57018290 (git)
Affected: 85df533a787bf07bf4367ce2a02b822ff1fba1a3 , < a64aa7db39392add5be09dffaedbf1f0ce5554df (git)
Affected: 85df533a787bf07bf4367ce2a02b822ff1fba1a3 , < 198824ccfa64ffebd918bf99c939bd8170a4a4d8 (git)
Affected: 85df533a787bf07bf4367ce2a02b822ff1fba1a3 , < 579a752464a64cb5f9139102f0e6b90a1f595ceb (git)
Affected: 0f21cc29bc13e86512621727a4388c8a7ad2716b (git)

Linux

Affected: 6.11
Unaffected: 0 , < 6.11 (semver)
Unaffected: 6.1.167 , ≤ 6.1.* (semver)
Unaffected: 6.6.130 , ≤ 6.6.* (semver)
Unaffected: 6.12.78 , ≤ 6.12.* (semver)
Unaffected: 6.18.17 , ≤ 6.18.* (semver)
Unaffected: 6.19.7 , ≤ 6.19.* (semver)
Unaffected: 7.0-rc3 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/mptcp/pm_kernel.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "c5c877e140e5f46023a74a51e577ce5edd0a4be7",
              "status": "affected",
              "version": "d93cf38fad9f66397093432b8917971a92ee0146",
              "versionType": "git"
            },
            {
              "lessThan": "05799c2f1ca5eb13d65764dda688d02021b65e06",
              "status": "affected",
              "version": "64815ba15880ce5f99df075fa4104fef170ac7e5",
              "versionType": "git"
            },
            {
              "lessThan": "67f34ab318807989b57dfdb0f79e2d4e57018290",
              "status": "affected",
              "version": "85df533a787bf07bf4367ce2a02b822ff1fba1a3",
              "versionType": "git"
            },
            {
              "lessThan": "a64aa7db39392add5be09dffaedbf1f0ce5554df",
              "status": "affected",
              "version": "85df533a787bf07bf4367ce2a02b822ff1fba1a3",
              "versionType": "git"
            },
            {
              "lessThan": "198824ccfa64ffebd918bf99c939bd8170a4a4d8",
              "status": "affected",
              "version": "85df533a787bf07bf4367ce2a02b822ff1fba1a3",
              "versionType": "git"
            },
            {
              "lessThan": "579a752464a64cb5f9139102f0e6b90a1f595ceb",
              "status": "affected",
              "version": "85df533a787bf07bf4367ce2a02b822ff1fba1a3",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "0f21cc29bc13e86512621727a4388c8a7ad2716b",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/mptcp/pm_kernel.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.11"
            },
            {
              "lessThan": "6.11",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.167",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.130",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.78",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.17",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0-rc3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.167",
                  "versionStartIncluding": "6.1.106",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.130",
                  "versionStartIncluding": "6.6.46",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.78",
                  "versionStartIncluding": "6.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.17",
                  "versionStartIncluding": "6.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.7",
                  "versionStartIncluding": "6.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0-rc3",
                  "versionStartIncluding": "6.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.10.5",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: pm: in-kernel: always mark signal+subflow endp as used\n\nSyzkaller managed to find a combination of actions that was generating\nthis warning:\n\n  msk-\u003epm.local_addr_used == 0\n  WARNING: net/mptcp/pm_kernel.c:1071 at __mark_subflow_endp_available net/mptcp/pm_kernel.c:1071 [inline], CPU#1: syz.2.17/961\n  WARNING: net/mptcp/pm_kernel.c:1071 at mptcp_nl_remove_subflow_and_signal_addr net/mptcp/pm_kernel.c:1103 [inline], CPU#1: syz.2.17/961\n  WARNING: net/mptcp/pm_kernel.c:1071 at mptcp_pm_nl_del_addr_doit+0x81d/0x8f0 net/mptcp/pm_kernel.c:1210, CPU#1: syz.2.17/961\n  Modules linked in:\n  CPU: 1 UID: 0 PID: 961 Comm: syz.2.17 Not tainted 6.19.0-08368-gfafda3b4b06b #22 PREEMPT(full)\n  Hardware name: QEMU Ubuntu 25.10 PC v2 (i440FX + PIIX, + 10.1 machine, 1996), BIOS 1.17.0-debian-1.17.0-1build1 04/01/2014\n  RIP: 0010:__mark_subflow_endp_available net/mptcp/pm_kernel.c:1071 [inline]\n  RIP: 0010:mptcp_nl_remove_subflow_and_signal_addr net/mptcp/pm_kernel.c:1103 [inline]\n  RIP: 0010:mptcp_pm_nl_del_addr_doit+0x81d/0x8f0 net/mptcp/pm_kernel.c:1210\n  Code: 89 c5 e8 46 30 6f fe e9 21 fd ff ff 49 83 ed 80 e8 38 30 6f fe 4c 89 ef be 03 00 00 00 e8 db 49 df fe eb ac e8 24 30 6f fe 90 \u003c0f\u003e 0b 90 e9 1d ff ff ff e8 16 30 6f fe eb 05 e8 0f 30 6f fe e8 9a\n  RSP: 0018:ffffc90001663880 EFLAGS: 00010293\n  RAX: ffffffff82de1a6c RBX: 0000000000000000 RCX: ffff88800722b500\n  RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000\n  RBP: ffff8880158b22d0 R08: 0000000000010425 R09: ffffffffffffffff\n  R10: ffffffff82de18ba R11: 0000000000000000 R12: ffff88800641a640\n  R13: ffff8880158b1880 R14: ffff88801ec3c900 R15: ffff88800641a650\n  FS:  00005555722c3500(0000) GS:ffff8880f909d000(0000) knlGS:0000000000000000\n  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n  CR2: 00007f66346e0f60 CR3: 000000001607c000 CR4: 0000000000350ef0\n  Call Trace:\n   \u003cTASK\u003e\n   genl_family_rcv_msg_doit+0x117/0x180 net/netlink/genetlink.c:1115\n   genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]\n   genl_rcv_msg+0x3a8/0x3f0 net/netlink/genetlink.c:1210\n   netlink_rcv_skb+0x16d/0x240 net/netlink/af_netlink.c:2550\n   genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219\n   netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]\n   netlink_unicast+0x3e9/0x4c0 net/netlink/af_netlink.c:1344\n   netlink_sendmsg+0x4aa/0x5b0 net/netlink/af_netlink.c:1894\n   sock_sendmsg_nosec net/socket.c:727 [inline]\n   __sock_sendmsg+0xc9/0xf0 net/socket.c:742\n   ____sys_sendmsg+0x272/0x3b0 net/socket.c:2592\n   ___sys_sendmsg+0x2de/0x320 net/socket.c:2646\n   __sys_sendmsg net/socket.c:2678 [inline]\n   __do_sys_sendmsg net/socket.c:2683 [inline]\n   __se_sys_sendmsg net/socket.c:2681 [inline]\n   __x64_sys_sendmsg+0x110/0x1a0 net/socket.c:2681\n   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n   do_syscall_64+0x143/0x440 arch/x86/entry/syscall_64.c:94\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n  RIP: 0033:0x7f66346f826d\n  Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 \u003c48\u003e 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48\n  RSP: 002b:00007ffc83d8bdc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e\n  RAX: ffffffffffffffda RBX: 00007f6634985fa0 RCX: 00007f66346f826d\n  RDX: 00000000040000b0 RSI: 0000200000000740 RDI: 0000000000000007\n  RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000\n  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6634985fa8\n  R13: 00007f6634985fac R14: 0000000000000000 R15: 0000000000001770\n   \u003c/TASK\u003e\n\nThe actions that caused that seem to be:\n\n - Set the MPTCP subflows limit to 0\n - Create an MPTCP endpoint with both the \u0027signal\u0027 and \u0027subflow\u0027 flags\n - Create a new MPTCP connection from a different address: an ADD_ADDR\n   linked to the MPTCP endpoint will be sent (\u0027signal\u0027 flag), but no\n   subflows is initiated (\u0027subflow\u0027 flag)\n - Remove the MPTCP endpoint\n\n---truncated---"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-25T10:27:15.125Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/c5c877e140e5f46023a74a51e577ce5edd0a4be7"
        },
        {
          "url": "https://git.kernel.org/stable/c/05799c2f1ca5eb13d65764dda688d02021b65e06"
        },
        {
          "url": "https://git.kernel.org/stable/c/67f34ab318807989b57dfdb0f79e2d4e57018290"
        },
        {
          "url": "https://git.kernel.org/stable/c/a64aa7db39392add5be09dffaedbf1f0ce5554df"
        },
        {
          "url": "https://git.kernel.org/stable/c/198824ccfa64ffebd918bf99c939bd8170a4a4d8"
        },
        {
          "url": "https://git.kernel.org/stable/c/579a752464a64cb5f9139102f0e6b90a1f595ceb"
        }
      ],
      "title": "mptcp: pm: in-kernel: always mark signal+subflow endp as used",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-23321",
    "datePublished": "2026-03-25T10:27:15.125Z",
    "dateReserved": "2026-01-13T15:37:45.996Z",
    "dateUpdated": "2026-03-25T10:27:15.125Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date

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.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-CP65-XQ47-M66J

CVE-2026-23321 (GCVE-0-2026-23321)

Tags

Sightings

Nomenclature