{
  "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-2026-89554",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-89554",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-09-11T19:44:27.586Z",
    "updatedAt": "2026-10-19T08:48:47.068Z",
    "importedAt": "2026-10-24T01:58:35.090Z",
    "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: fix uninitialized local_id in syncookie MP_JOIN reconstruction",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: fix uninitialized local_id in syncookie MP_JOIN reconstruction\n\nmptcp_token_join_cookie_init_state() restores remote_nonce, local_nonce,\nbackup, join_id, token and msk from the saved cookie entry when rebuilding\nthe request socket for a MP_JOIN 4th-ACK handled under SYN cookies, but it\ndoes not restore local_id, even though the SYN path saved it.\nsubflow_ulp_clone() then reads that uninitialized field and stores it as\nthe joined subflow's address-ID. Because the request-sock slab is\nSLAB_TYPESAFE_BY_RCU and not zeroed on allocation, the value is the stale\nbyte of a previously freed request socket, which an off-path peer can\ninfluence by sending concurrent MP_JOIN SYNs. This corrupts the path\nmanager's id-based subflow bookkeeping for the connection.\n\nRestore subflow_req->local_id from the cookie entry, as done for the other\nfields.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "9466a1ccebbe54ac57fb8a89c2b4b854826546a8",
              "status": "affected",
              "versionType": "git",
              "lessThan": "4534e0eead692bb069ad1e6a5a245fc2e2078300"
            },
            {
              "version": "9466a1ccebbe54ac57fb8a89c2b4b854826546a8",
              "status": "affected",
              "versionType": "git",
              "lessThan": "63cacb05e51a1c6e1349d2e593d00fd6ef43def4"
            },
            {
              "version": "9466a1ccebbe54ac57fb8a89c2b4b854826546a8",
              "status": "affected",
              "versionType": "git",
              "lessThan": "954b5ea836eb118d188975ced803448537ab8479"
            },
            {
              "version": "9466a1ccebbe54ac57fb8a89c2b4b854826546a8",
              "status": "affected",
              "versionType": "git",
              "lessThan": "9df36a4846375a9b75bf42d77bfed216b0f366f9"
            },
            {
              "version": "9466a1ccebbe54ac57fb8a89c2b4b854826546a8",
              "status": "affected",
              "versionType": "git",
              "lessThan": "64f2c5dd49b956a542c8c02b8dad5d262a462bba"
            },
            {
              "version": "9466a1ccebbe54ac57fb8a89c2b4b854826546a8",
              "status": "affected",
              "versionType": "git",
              "lessThan": "51887ccd88791ddaa8755a7c614fda031ecf7982"
            },
            {
              "version": "9466a1ccebbe54ac57fb8a89c2b4b854826546a8",
              "status": "affected",
              "versionType": "git",
              "lessThan": "bf19d166337c6488b39cb03eeeffb30a941d6326"
            },
            {
              "version": "9466a1ccebbe54ac57fb8a89c2b4b854826546a8",
              "status": "affected",
              "versionType": "git",
              "lessThan": "b878dfdd12d7a5b8722a78d35e313506140ca3d9"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "5.9",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "5.9"
            },
            {
              "version": "5.10.270",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "version": "5.15.221",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "version": "6.1.188",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "version": "6.6.157",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.109",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.18.50",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "7.2.4",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "version": "7.3",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}