{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74588","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-15T05:44:03.918Z","datePublished":"2026-08-22T15:31:40.466Z","dateUpdated":"2026-08-25T05:40:15.097Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-25T05:40:15.097Z"},"descriptions":[{"lang":"en","value":"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>"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - The bug is reached when the kernel SCTP stack processes inbound SACK and ASCONF chunks from a remote association peer via sctp_rcv()/sctp_inq_push(), with no local syscall or ioctl required on the victim.\nAC:L - The remote peer controls the SCTP protocol sequence (gap SACKs, ADDIP multihoming, ASCONF Delete-IP, and SACK reneging) needed to strand a chunk and free its transport; no attacker-uncontrollable race or rare memory layout is required.\nPR:N - Exploitation requires only network access as an established SCTP association peer sending authenticated protocol traffic; no local Linux account, capability, or namespace privilege is needed on the victim host.\nUI:N - No victim user action is required beyond normal automated SCTP server/client operation; the attacker drives the entire trigger sequence with crafted SACK and ASCONF packets on the existing association.\nS:U - Impact is confined to kernel memory corruption and potential privilege escalation within the host kernel; it does not cross a VM, container, or IOMMU security boundary.\nC:H - KASAN reports a slab use-after-free read through dangling chunk->transport in sctp_check_transmitted(); UAF on sctp_transport objects can be groomed for arbitrary kernel memory disclosure.\nI:H - The UAF dereference performs flight_size arithmetic on a freed sctp_transport slab object, enabling heap grooming and arbitrary kernel write or control-flow hijack primitives typical of SCTP transport UAFs.\nA:H - Accessing freed transport memory during SACK processing can cause kernel oops/panic and repeatable remote denial of service against any SCTP endpoint handling the malicious peer traffic."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sctp/outqueue.c"],"versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"6575fb17230814b48b471727c8410c0aadff9274","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"6b9e2ea2057113f3393990ba646d2d97c719a80d","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"874a7c2b5e184f06134fdfde27e9ce9271bafe58","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"1adf929121e13e0b19200bb9fef715b918d483fe","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"e2e7c1de0e226ca1b7fea2de57a6c9bca408709b","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"2b3b5eec8b2c30ee237e3c31a6a38de9c39d804d","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"5ccf35ef0ed6059cdf8b1f4606a6584d5b67166b","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"9f2cf069a9a72a2d6b97ca8b4c70e714aac99749","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sctp/outqueue.c"],"versions":[{"version":"2.6.12","status":"affected"},{"version":"0","lessThan":"2.6.12","status":"unaffected","versionType":"semver"},{"version":"5.10.265","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.216","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.183","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.152","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.104","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.45","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.9","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.10.265"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.15.216"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.1.183"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.6.152"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.12.104"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.18.45"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.1.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/6575fb17230814b48b471727c8410c0aadff9274"},{"url":"https://git.kernel.org/stable/c/6b9e2ea2057113f3393990ba646d2d97c719a80d"},{"url":"https://git.kernel.org/stable/c/874a7c2b5e184f06134fdfde27e9ce9271bafe58"},{"url":"https://git.kernel.org/stable/c/1adf929121e13e0b19200bb9fef715b918d483fe"},{"url":"https://git.kernel.org/stable/c/e2e7c1de0e226ca1b7fea2de57a6c9bca408709b"},{"url":"https://git.kernel.org/stable/c/2b3b5eec8b2c30ee237e3c31a6a38de9c39d804d"},{"url":"https://git.kernel.org/stable/c/5ccf35ef0ed6059cdf8b1f4606a6584d5b67166b"},{"url":"https://git.kernel.org/stable/c/9f2cf069a9a72a2d6b97ca8b4c70e714aac99749"}],"title":"sctp: keep chunk->transport in step with the list it is queued on","x_generator":{"engine":"bippy-1.2.0"}}}}