CVE-2026-64564

Description

In the Linux kernel, the following vulnerability has been resolved: sctp: don't free the ASCONF's own transport in DEL-IP processing sctp_process_asconf() caches the transport the ASCONF chunk is processed against in asconf->transport (== chunk->transport, set once in sctp_rcv()). For an ASCONF located through its Address Parameter by __sctp_rcv_asconf_lookup(), that cached transport corresponds to the Address Parameter, which need not be the packet's source address. sctp_process_asconf_param() rejects a DEL-IP for the packet source address (ADDIP D8, SCTP_ERROR_DEL_SRC_IP), but nothing protects asconf->transport. A single ASCONF can therefore carry, in order: [Address Parameter L] [DEL-IP L] [DEL-IP 0.0.0.0] where L differs from the source. The DEL-IP for L passes the D8 check and calls sctp_assoc_rm_peer() on the transport that asconf->transport still points at, freeing it (RCU-deferred). The following wildcard DEL-IP then reuses the now-dangling asconf->transport in sctp_assoc_set_primary() and sctp_assoc_del_nonprimary_peers(): set_primary() dereferences the freed transport (->ipaddr, ->state) and plants the dangling pointer into asoc->peer.primary_path / active_path, and del_nonprimary_peers(), keeping only the pointer that is no longer on the list, removes every real transport, leaving the association with a transport_count of 0 and primary_path/active_path pointing at freed memory. Reject a DEL-IP that targets the transport the ASCONF is being processed against, mirroring the existing source-address guard, so the wildcard branch can never reuse a freed transport.

Overview

State: PUBLISHED
Assigner (CNA): Linux
CVSS severity: —
CVSS score: —
CVSS vector: —
Effective score: no score available from CNA, NVD, or AI yet
CWE(s): —
Reserved: 2026-07-19
Published: 2026-08-04 06:23 UTC
Last updated: 2026-08-04 06:23 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/64xxx/CVE-2026-64564.json

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Affected products (2)

Vendor	Product	Versions	Platforms
Linux	Linux	`42e30bf3463cd37d73839376662cb79b4d5c416c` (affected), `42e30bf3463cd37d73839376662cb79b4d5c416c` (affected), `42e30bf3463cd37d73839376662cb79b4d5c416c` (affected), `42e30bf3463cd37d73839376662cb79b4d5c416c` (affected), `42e30bf3463cd37d73839376662cb79b4d5c416c` (affected)	—
Linux	Linux	`2.6.25` (affected), `0` (unaffected), `6.6.148` (unaffected), `6.12.101` (unaffected), `6.18.42` (unaffected), `7.1.6` (unaffected), `7.2-rc5` (unaffected)	—

Vendor references (5)

References embedded in the original CVE record by the assigning CNA.

Web references (0)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

No web references attached yet.

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-64564.json.

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/sctp/sm_make_chunk.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "fedeb4468987bcaff85fe3061de5ae052d414740",
              "status": "affected",
              "version": "42e30bf3463cd37d73839376662cb79b4d5c416c",
              "versionType": "git"
            },
            {
              "lessThan": "74e8f3e7114f0e26d1b2c4c048044db9fcc27603",
              "status": "affected",
              "version": "42e30bf3463cd37d73839376662cb79b4d5c416c",
              "versionType": "git"
            },
            {
              "lessThan": "85aca407c560aba81b5ce9d3d6cf94c74077d19b",
              "status": "affected",
              "version": "42e30bf3463cd37d73839376662cb79b4d5c416c",
              "versionType": "git"
            },
            {
              "lessThan": "d136b29bf91dd8e3161281b87de597b7311d9462",
              "status": "affected",
              "version": "42e30bf3463cd37d73839376662cb79b4d5c416c",
              "versionType": "git"
            },
            {
              "lessThan": "9b2854f86f0b56e9027d68e7a3fc909d1a9b566f",
              "status": "affected",
              "version": "42e30bf3463cd37d73839376662cb79b4d5c416c",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/sctp/sm_make_chunk.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.25"
            },
            {
              "lessThan": "2.6.25",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.148",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.101",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.42",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc5",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.148",
                  "versionStartIncluding": "2.6.25",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.101",
                  "versionStartIncluding": "2.6.25",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.42",
                  "versionStartIncluding": "2.6.25",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.6",
                  "versionStartIncluding": "2.6.25",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2-rc5",
                  "versionStartIncluding": "2.6.25",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: don't free the ASCONF's own transport in DEL-IP processing\n\nsctp_process_asconf() caches the transport the ASCONF chunk is processed\nagainst in asconf->transport (== chunk->transport, set once in sctp_rcv()).\nFor an ASCONF located through its Address Parameter by\n__sctp_rcv_asconf_lookup(), that cached transport corresponds to the\nAddress Parameter, which need not be the packet's source address.\n\nsctp_process_asconf_param() rejects a DEL-IP for the packet source address\n(ADDIP D8, SCTP_ERROR_DEL_SRC_IP), but nothing protects asconf->transport.\nA single ASCONF can therefore carry, in order:\n\n    [Address Parameter L] [DEL-IP L] [DEL-IP 0.0.0.0]\n\nwhere L differs from the source. The DEL-IP for L passes the D8 check and\ncalls sctp_assoc_rm_peer() on the transport that asconf->transport still\npoints at, freeing it (RCU-deferred). The following wildcard DEL-IP then\nreuses the now-dangling asconf->transport in sctp_assoc_set_primary() and\nsctp_assoc_del_nonprimary_peers(): set_primary() dereferences the freed\ntransport (->ipaddr, ->state) and plants the dangling pointer into\nasoc->peer.primary_path / active_path, and del_nonprimary_peers(), keeping\nonly the pointer that is no longer on the list, removes every real\ntransport, leaving the association with a transport_count of 0 and\nprimary_path/active_path pointing at freed memory.\n\nReject a DEL-IP that targets the transport the ASCONF is being processed\nagainst, mirroring the existing source-address guard, so the wildcard\nbranch can never reuse a freed transport."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-04T06:23:23.339Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/fedeb4468987bcaff85fe3061de5ae052d414740"
        },
        {
          "url": "https://git.kernel.org/stable/c/74e8f3e7114f0e26d1b2c4c048044db9fcc27603"
        },
        {
          "url": "https://git.kernel.org/stable/c/85aca407c560aba81b5ce9d3d6cf94c74077d19b"
        },
        {
          "url": "https://git.kernel.org/stable/c/d136b29bf91dd8e3161281b87de597b7311d9462"
        },
        {
          "url": "https://git.kernel.org/stable/c/9b2854f86f0b56e9027d68e7a3fc909d1a9b566f"
        }
      ],
      "title": "sctp: don't free the ASCONF's own transport in DEL-IP processing",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64564",
    "datePublished": "2026-08-04T06:23:23.339Z",
    "dateReserved": "2026-07-19T15:36:31.797Z",
    "dateUpdated": "2026-08-04T06:23:23.339Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}