{
  "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-2026-31662",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-31662",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-04-24T14:45:12.593Z",
    "updatedAt": "2026-10-19T18:56:02.280Z",
    "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": "tipc: fix bc_ackers underflow on duplicate GRP_ACK_MSG",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: fix bc_ackers underflow on duplicate GRP_ACK_MSG\n\nThe GRP_ACK_MSG handler in tipc_group_proto_rcv() currently decrements\nbc_ackers on every inbound group ACK, even when the same member has\nalready acknowledged the current broadcast round.\n\nBecause bc_ackers is a u16, a duplicate ACK received after the last\nlegitimate ACK wraps the counter to 65535. Once wrapped,\ntipc_group_bc_cong() keeps reporting congestion and later group\nbroadcasts on the affected socket stay blocked until the group is\nrecreated.\n\nFix this by ignoring duplicate or stale ACKs before touching bc_acked or\nbc_ackers. This makes repeated GRP_ACK_MSG handling idempotent and\nprevents the underflow path.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "2f487712b89376fce267223bbb0db93d393d4b09",
              "status": "affected",
              "versionType": "git",
              "lessThan": "a7db57ccca21f5801609065473c89a38229ecb92"
            },
            {
              "version": "2f487712b89376fce267223bbb0db93d393d4b09",
              "status": "affected",
              "versionType": "git",
              "lessThan": "36ec4fdd6250dcd5e73eb09ea92ed92e9cc28412"
            },
            {
              "version": "2f487712b89376fce267223bbb0db93d393d4b09",
              "status": "affected",
              "versionType": "git",
              "lessThan": "575faea557f1a184a5f09661bd47ebd3ef3769f8"
            },
            {
              "version": "2f487712b89376fce267223bbb0db93d393d4b09",
              "status": "affected",
              "versionType": "git",
              "lessThan": "3bcf7aca63f0bcd679ae28e9b99823c608e59ce3"
            },
            {
              "version": "2f487712b89376fce267223bbb0db93d393d4b09",
              "status": "affected",
              "versionType": "git",
              "lessThan": "a2ea1ef0167d7a84730638d05c20ccdc421b14b6"
            },
            {
              "version": "2f487712b89376fce267223bbb0db93d393d4b09",
              "status": "affected",
              "versionType": "git",
              "lessThan": "1b6f13f626665cac67ba5a012765427680518711"
            },
            {
              "version": "2f487712b89376fce267223bbb0db93d393d4b09",
              "status": "affected",
              "versionType": "git",
              "lessThan": "e0bb732eaf77f9ac2f2638bdac9e39b81e0a9682"
            },
            {
              "version": "2f487712b89376fce267223bbb0db93d393d4b09",
              "status": "affected",
              "versionType": "git",
              "lessThan": "48a5fe38772b6f039522469ee6131a67838221a8"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "4.15",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "4.15"
            },
            {
              "version": "5.10.253",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "version": "5.15.203",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "version": "6.1.169",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "version": "6.6.135",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.82",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.18.23",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "6.19.13",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.19.*"
            },
            {
              "version": "7.0",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}