{"id":"CVE-2026-74688","summary":"sctp: clear control chunk transport if it is being removed","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: clear control chunk transport if it is being removed\n\nsctp_make_heartbeat_ack() caches the destination transport in\nchunk-\u003etransport without taking a reference. When src_out_of_asoc_ok is\nenabled, the HEARTBEAT ACK may remain queued on control_chunk_list instead\nof being transmitted immediately.\n\nIf the peer transport is removed while the chunk is still queued,\nsctp_assoc_rm_peer() drops the transport and schedules it for RCU freeing,\nbut only clears cached transport pointers in out_chunk_list.  The queued\ncontrol chunk therefore retains a dangling transport pointer.\n\nOnce an ASCONF_ACK clears the suppression and the queued control chunk is\ntransmitted, SCTP dereferences the stale transport pointer, leading to a\nuse-after-free.\n\nFix this by also clearing chunk-\u003etransport for queued control chunks in\ncontrol_chunk_list when removing the transport.","modified":"2026-08-27T11:30:45.896268029Z","published":"2026-08-22T15:32:53.423Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74688.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/18d704bdd809377dfd81a3c2f42426763b5da227"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4d6b9cac6df5e0cfef1a66b3edd7aebdb9e4b7e7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6160e756db81d6cb63e3e2952efcf6c5134be385"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8de65194a04d2552cd39b6c67d942d490f22d174"},{"type":"WEB","url":"https://git.kernel.org/stable/c/936658ec41c28c397ef390140e02d4c91ade92f0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c9158ceaf27780ef64534ad72f44ffde3f8ccc49"},{"type":"WEB","url":"https://git.kernel.org/stable/c/dbb3f418a8665ffb0514e1a9520ab6a1c5d4d886"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fad4766a74220fe579c6fcaa10ba01c23529814f"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74688.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74688"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"8a07eb0a50aebc8c95478d49c28c7f8419a26cef"},{"fixed":"dbb3f418a8665ffb0514e1a9520ab6a1c5d4d886"},{"fixed":"fad4766a74220fe579c6fcaa10ba01c23529814f"},{"fixed":"936658ec41c28c397ef390140e02d4c91ade92f0"},{"fixed":"8de65194a04d2552cd39b6c67d942d490f22d174"},{"fixed":"6160e756db81d6cb63e3e2952efcf6c5134be385"},{"fixed":"18d704bdd809377dfd81a3c2f42426763b5da227"},{"fixed":"4d6b9cac6df5e0cfef1a66b3edd7aebdb9e4b7e7"},{"fixed":"c9158ceaf27780ef64534ad72f44ffde3f8ccc49"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74688.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.1.0"},{"fixed":"5.10.265"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.216"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.183"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.152"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.104"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.45"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.9"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74688.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}