{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74688", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.926Z", "datePublished": "2026-08-22T15:32:53.423Z", "dateUpdated": "2026-10-16T19:16:09.209Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-25T05:41:32.712Z" }, "descriptions": [ { "lang": "en", "value": "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->transport 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->transport for queued control chunks in\ncontrol_chunk_list when removing the transport." } ], "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 from remotely received SCTP packets (HEARTBEAT, ASCONF, ASCONF_ACK) processed in sctp_rcv() and the association input state machine on internet-facing SCTP servers and telecom endpoints.\nAC:L - A remote SCTP peer controls packet sequencing and can send HEARTBEAT while src_out_of_asoc_ok blocks transmission, remove transports via ASCONF DEL_IP, then trigger flush when ASCONF_ACK clears suppression.\nPR:N - Exploitation requires only a network-reachable established SCTP association; the attacker needs no Linux credentials, capabilities, or namespaces—only the ability to send valid SCTP traffic to the target.\nUI:N - No victim user action is required; the use-after-free is triggered entirely by SCTP protocol messages sent by a remote peer during normal association operation or address migration.\nS:U - Impact is confined to kernel memory corruption and privilege escalation within the host kernel; it does not cross VM, container, or IOMMU security boundaries.\nC:H - Stale chunk->transport pointers dereference RCU-freed sctp_transport objects in sctp_outq_select_transport() and sctp_packet_transmit(), a use-after-free that enables arbitrary kernel memory disclosure via heap grooming.\nI:H - Use-after-free of sctp_transport allows controlled reuse of freed kmalloc objects, providing a standard path to arbitrary kernel writes and local privilege escalation or remote code execution in kernel context.\nA:H - Dereferencing the freed transport during control-chunk transmission can immediately kernel oops or panic the system; use-after-free bugs inherently threaten availability even when full exploitation is not attempted." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sctp/associola.c" ], "versions": [ { "version": "8a07eb0a50aebc8c95478d49c28c7f8419a26cef", "lessThan": "dbb3f418a8665ffb0514e1a9520ab6a1c5d4d886", "status": "affected", "versionType": "git" }, { "version": "8a07eb0a50aebc8c95478d49c28c7f8419a26cef", "lessThan": "fad4766a74220fe579c6fcaa10ba01c23529814f", "status": "affected", "versionType": "git" }, { "version": "8a07eb0a50aebc8c95478d49c28c7f8419a26cef", "lessThan": "936658ec41c28c397ef390140e02d4c91ade92f0", "status": "affected", "versionType": "git" }, { "version": "8a07eb0a50aebc8c95478d49c28c7f8419a26cef", "lessThan": "8de65194a04d2552cd39b6c67d942d490f22d174", "status": "affected", "versionType": "git" }, { "version": "8a07eb0a50aebc8c95478d49c28c7f8419a26cef", "lessThan": "6160e756db81d6cb63e3e2952efcf6c5134be385", "status": "affected", "versionType": "git" }, { "version": "8a07eb0a50aebc8c95478d49c28c7f8419a26cef", "lessThan": "18d704bdd809377dfd81a3c2f42426763b5da227", "status": "affected", "versionType": "git" }, { "version": "8a07eb0a50aebc8c95478d49c28c7f8419a26cef", "lessThan": "4d6b9cac6df5e0cfef1a66b3edd7aebdb9e4b7e7", "status": "affected", "versionType": "git" }, { "version": "8a07eb0a50aebc8c95478d49c28c7f8419a26cef", "lessThan": "c9158ceaf27780ef64534ad72f44ffde3f8ccc49", "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/associola.c" ], "versions": [ { "version": "3.1", "status": "affected" }, { "version": "0", "lessThan": "3.1", "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": "3.1", "versionEndExcluding": "5.10.265" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "5.15.216" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "6.1.183" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "6.6.152" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "6.12.104" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "6.18.45" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "7.1.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/dbb3f418a8665ffb0514e1a9520ab6a1c5d4d886" }, { "url": "https://git.kernel.org/stable/c/fad4766a74220fe579c6fcaa10ba01c23529814f" }, { "url": "https://git.kernel.org/stable/c/936658ec41c28c397ef390140e02d4c91ade92f0" }, { "url": "https://git.kernel.org/stable/c/8de65194a04d2552cd39b6c67d942d490f22d174" }, { "url": "https://git.kernel.org/stable/c/6160e756db81d6cb63e3e2952efcf6c5134be385" }, { "url": "https://git.kernel.org/stable/c/18d704bdd809377dfd81a3c2f42426763b5da227" }, { "url": "https://git.kernel.org/stable/c/4d6b9cac6df5e0cfef1a66b3edd7aebdb9e4b7e7" }, { "url": "https://git.kernel.org/stable/c/c9158ceaf27780ef64534ad72f44ffde3f8ccc49" } ], "title": "sctp: clear control chunk transport if it is being removed", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-74688", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "yes" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T19:14:32.502704Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:16:09.209Z" } } ] } }