{"id":"CVE-2026-74588","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-74588","summary":"sctp: keep chunk->transport in step with the list it is queued on","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: keep chunk->transport in step with the list it is queued on\n\n__sctp_outq_flush_rtx() moves a gap-acked chunk onto another transport's\ntransmitted list without updating chunk->transport:\n\n\tif (chunk->tsn_gap_acked) {\n\t\tlist_move_tail(&chunk->transmitted_list,\n\t\t\t       &transport->transmitted);\n\t\tcontinue;\n\t}\n\nThe chunk then sits on a live transport's list while chunk->transport still\nnames a different one.  If that transport is removed - sctp_assoc_rm_peer()\nfrom an ASCONF Delete-IP - sctp_transport_free() RCU-frees it and the chunk\nis left with a dangling pointer.  sctp_assoc_rm_peer() scrubs\npeer->transmitted and asoc->outqueue.out_chunk_list, but the chunk is on\nneither.\n\nThe pointer is not followed while tsn_gap_acked is set.  A SACK that\nreneges on the TSN clears the flag, and the next SACK reaches\n\n\ttchunk->transport->flight_size -= sctp_data_size(tchunk);\n\ninside the freed transport.  KASAN reports a slab-use-after-free read in\nsctp_check_transmitted(), freed from sctp_assoc_rm_peer().  Both the\nremoval and the SACKs come from the association peer.\n\nSet chunk->transport at the move.  The ordinary resend path needs nothing:\nit reaches its list_move_tail() only after sctp_packet_append_chunk()\nreturned SCTP_XMIT_OK, and __sctp_packet_append_chunk() has rebound the\nchunk by then.\n\nDiscovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>","published":"2026-08-22T15:31:40.466Z","modified":"2026-08-24T11:46:59.309552164Z","cvss":null,"epss":{"score":0.00177,"percentile":0.072,"asOf":"2026-08-24"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"5.10.265"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/1adf929121e13e0b19200bb9fef715b918d483fe"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2b3b5eec8b2c30ee237e3c31a6a38de9c39d804d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5ccf35ef0ed6059cdf8b1f4606a6584d5b67166b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6575fb17230814b48b471727c8410c0aadff9274"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6b9e2ea2057113f3393990ba646d2d97c719a80d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/874a7c2b5e184f06134fdfde27e9ce9271bafe58"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9f2cf069a9a72a2d6b97ca8b4c70e714aac99749"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e2e7c1de0e226ca1b7fea2de57a6c9bca408709b"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74588.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74588"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-24T11:46:59.309552164Z"}}