# CVE-2026-64564: CVE-2026-64564

Status: published. Published: 2026-08-04. Updated: 2026-11-03.

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.

## Remediation

No remediation reported in collected sources

## Affected products and versions

Not reported in collected sources.

## Severity and prioritization

- CVSS 3.1: 9.8 (critical); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H; source: NVD: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: exploitation none; automatable yes; technical impact total; source NVD SSVC: 134c704f-9b21-4f2e-91b3-4a467353bcc0

- Weaknesses: CWE-416

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://git.kernel.org/stable/c/2b324ba3494ae958cba16a453e3e71489b4de7fc (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

- https://git.kernel.org/stable/c/74e8f3e7114f0e26d1b2c4c048044db9fcc27603 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

- https://git.kernel.org/stable/c/85aca407c560aba81b5ce9d3d6cf94c74077d19b (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

- https://git.kernel.org/stable/c/9b2854f86f0b56e9027d68e7a3fc909d1a9b566f (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

- https://git.kernel.org/stable/c/a63afa1f9b12d5293cbe0b77fd45dc0632533a13 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

- https://git.kernel.org/stable/c/a9ce31be4cb1a5dd82b3e0a1d0c3e7cbdcd31293 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

- https://git.kernel.org/stable/c/d136b29bf91dd8e3161281b87de597b7311d9462 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

- https://git.kernel.org/stable/c/fedeb4468987bcaff85fe3061de5ae052d414740 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

- https://matrix.tencent.com/en/2026/08/06/sctphantom-CVE-2026-64564 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)

- http://www.openwall.com/lists/oss-security/2026/08/06/13 (af854a3a-2127-422b-91ae-364da2661108)

- http://www.openwall.com/lists/oss-security/2026/08/06/3 (af854a3a-2127-422b-91ae-364da2661108)

- http://www.openwall.com/lists/oss-security/2026/08/06/4 (af854a3a-2127-422b-91ae-364da2661108)

- http://www.openwall.com/lists/oss-security/2026/08/07/1 (af854a3a-2127-422b-91ae-364da2661108)

- http://www.openwall.com/lists/oss-security/2026/08/07/2 (af854a3a-2127-422b-91ae-364da2661108)

- http://www.openwall.com/lists/oss-security/2026/08/07/8 (af854a3a-2127-422b-91ae-364da2661108)

## Provenance

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64564; retrieved 2026-11-03; source updated 2026-11-03

Revision: c36a3d0245ea077dad7c74a2d90e11d3b7e8fa21428685a64a79d2ebe5c709d2

Canonical: https://y2.dev/cve/CVE-2026-64564

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.