{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2026-23321",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-23321",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-03-25T10:27:15.125Z",
    "updatedAt": "2026-10-15T01:14:04.247Z",
    "importedAt": "2026-10-24T01:58:02.025Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "mptcp: pm: in-kernel: always mark signal+subflow endp as used",
      "summary": "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->pm.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 <0f> 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   <TASK>\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 <48> 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   </TASK>\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 'signal' and 'subflow' flags\n - Create a new MPTCP connection from a different address: an ADD_ADDR\n   linked to the MPTCP endpoint will be sent ('signal' flag), but no\n   subflows is initiated ('subflow' flag)\n - Remove the MPTCP endpoint\n\n---truncated---",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "d93cf38fad9f66397093432b8917971a92ee0146",
              "status": "affected",
              "versionType": "git",
              "lessThan": "c5c877e140e5f46023a74a51e577ce5edd0a4be7"
            },
            {
              "version": "64815ba15880ce5f99df075fa4104fef170ac7e5",
              "status": "affected",
              "versionType": "git",
              "lessThan": "05799c2f1ca5eb13d65764dda688d02021b65e06"
            },
            {
              "version": "85df533a787bf07bf4367ce2a02b822ff1fba1a3",
              "status": "affected",
              "versionType": "git",
              "lessThan": "67f34ab318807989b57dfdb0f79e2d4e57018290"
            },
            {
              "version": "85df533a787bf07bf4367ce2a02b822ff1fba1a3",
              "status": "affected",
              "versionType": "git",
              "lessThan": "a64aa7db39392add5be09dffaedbf1f0ce5554df"
            },
            {
              "version": "85df533a787bf07bf4367ce2a02b822ff1fba1a3",
              "status": "affected",
              "versionType": "git",
              "lessThan": "198824ccfa64ffebd918bf99c939bd8170a4a4d8"
            },
            {
              "version": "85df533a787bf07bf4367ce2a02b822ff1fba1a3",
              "status": "affected",
              "versionType": "git",
              "lessThan": "579a752464a64cb5f9139102f0e6b90a1f595ceb"
            },
            {
              "version": "0f21cc29bc13e86512621727a4388c8a7ad2716b",
              "status": "affected",
              "versionType": "git"
            },
            {
              "version": "6.1.106",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.1.167"
            },
            {
              "version": "6.6.46",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.6.130"
            },
            {
              "version": "6.10.5",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.11"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "6.11",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "6.11"
            },
            {
              "version": "6.1.167",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "version": "6.6.130",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.78",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.18.17",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "6.19.7",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.19.*"
            },
            {
              "version": "7.0",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}