CVE-2026-64564sctp: don't free the ASCONF's own transport in DEL-IP processing
- 9.8CriticalCVSS base score
- 1.4%Exploitation in 30 daysEPSS · top 27% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By Linux
- 16 days later
· 16 days later
Published
- 3 months later
· 3 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Analyzed | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 1.4% · top 27% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Affected products
- affected 42e30bf3463cd37d73839376662cb79b4d5c416c – < a9ce31be4cb1a5dd82b3e0a1d0c3e7cbdcd31293
- affected 42e30bf3463cd37d73839376662cb79b4d5c416c – < a63afa1f9b12d5293cbe0b77fd45dc0632533a13
- affected 42e30bf3463cd37d73839376662cb79b4d5c416c – < 2b324ba3494ae958cba16a453e3e71489b4de7fc
- affected 42e30bf3463cd37d73839376662cb79b4d5c416c – < fedeb4468987bcaff85fe3061de5ae052d414740
- affected 42e30bf3463cd37d73839376662cb79b4d5c416c – < 74e8f3e7114f0e26d1b2c4c048044db9fcc27603
- affected 42e30bf3463cd37d73839376662cb79b4d5c416c – < 85aca407c560aba81b5ce9d3d6cf94c74077d19b
- affected 42e30bf3463cd37d73839376662cb79b4d5c416c – < d136b29bf91dd8e3161281b87de597b7311d9462
- affected 42e30bf3463cd37d73839376662cb79b4d5c416c – < 9b2854f86f0b56e9027d68e7a3fc909d1a9b566f
- affected 2.6.25
- unaffected < 2.6.25
- unaffected 5.10.265 – ≤ 5.10.*
- unaffected 5.15.216 – ≤ 5.15.*
- unaffected 6.1.183 – ≤ 6.1.*
- unaffected 6.6.148 – ≤ 6.6.*
- unaffected 6.12.101 – ≤ 6.12.*
- unaffected 6.18.42 – ≤ 6.18.*
- unaffected 7.1.6 – ≤ 7.1.*
- unaffected 7.2 – ≤ *
References
References15
- https://git.kernel.org/stable/c/a9ce31be4cb1a5dd82b3e0a1d0c3e7cbdcd31293 (opens in a new tab)
- https://git.kernel.org/stable/c/a63afa1f9b12d5293cbe0b77fd45dc0632533a13 (opens in a new tab)
- https://git.kernel.org/stable/c/2b324ba3494ae958cba16a453e3e71489b4de7fc (opens in a new tab)
- https://git.kernel.org/stable/c/fedeb4468987bcaff85fe3061de5ae052d414740 (opens in a new tab)
- https://git.kernel.org/stable/c/74e8f3e7114f0e26d1b2c4c048044db9fcc27603 (opens in a new tab)
- https://git.kernel.org/stable/c/85aca407c560aba81b5ce9d3d6cf94c74077d19b (opens in a new tab)
- https://git.kernel.org/stable/c/d136b29bf91dd8e3161281b87de597b7311d9462 (opens in a new tab)
- https://git.kernel.org/stable/c/9b2854f86f0b56e9027d68e7a3fc909d1a9b566f (opens in a new tab)
- https://matrix.tencent.com/en/2026/08/06/sctphantom-CVE-2026-64564 (opens in a new tab)
- http://www.openwall.com/lists/oss-security/2026/08/06/3 (opens in a new tab)
- http://www.openwall.com/lists/oss-security/2026/08/06/4 (opens in a new tab)
- http://www.openwall.com/lists/oss-security/2026/08/06/13 (opens in a new tab)
- http://www.openwall.com/lists/oss-security/2026/08/07/1 (opens in a new tab)
- http://www.openwall.com/lists/oss-security/2026/08/07/2 (opens in a new tab)
- http://www.openwall.com/lists/oss-security/2026/08/07/8 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-52605 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-64564)Record last updated .