{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74587", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.918Z", "datePublished": "2026-08-22T15:31:39.810Z", "dateUpdated": "2026-10-16T19:05:58.841Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-25T05:40:13.798Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: fix use-after-free of cached ASCONF chunk\n\naddip_last_asconf caches the outstanding outbound ASCONF chunk. The normal\nASCONF-ACK completion path releases the chunk and clears the pointer.\n\nHowever, sctp_asconf_queue_teardown() releases the cached chunk without\nclearing addip_last_asconf. During peer restart handling,\nsctp_sf_do_dupcook_a() queues SCTP_CMD_PURGE_ASCONF_QUEUE, which invokes\nsctp_asconf_queue_teardown() while the association remains alive and leaves\nthe pointer dangling.\n\nA delayed authenticated ASCONF-ACK can then reach sctp_sf_do_asconf_ack(),\nwhich accesses the stale chunk and passes it to sctp_process_asconf_ack(),\ncausing a use-after-free and a second release.\n\nClearing the pointer exposes a race with T4 expiry. Peer restart handling\nqueues the timer stop before the purge, but SCTP_CMD_TIMER_STOP uses\ntimer_delete(), which does not wait for a callback already running on\nanother CPU. Such a callback can reach sctp_sf_t4_timer_expire() after\nthe purge and dereference NULL.\n\nClear addip_last_asconf after releasing the cached chunk, and make\nsctp_sf_t4_timer_expire() consume a stale T4 expiry if no outstanding\nASCONF remains." } ], "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 UAF is triggered when the kernel processes inbound SCTP COOKIE-ECHO (peer restart) and ASCONF-ACK chunks from a remote association peer via sctp_rcv()/sctp_inq_push()/sctp_do_sm(), with no local syscall required on the victim.\nAC:L - The remote SCTP peer controls the full protocol sequence—establishing an ADDIP-capable association, waiting for the victim's outstanding ASCONF, sending COOKIE-ECHO restart to purge queues, then delivering a delayed authenticated ASCONF-ACK—without attacker-uncontrollable races or memory layout.\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 COOKIE-ECHO and ASCONF-ACK 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 - sctp_sf_do_asconf_ack() and sctp_process_asconf_ack() dereference the stale addip_last_asconf pointer to read freed sctp_chunk and skb metadata; UAF on slab-allocated chunk objects enables heap grooming for arbitrary kernel memory disclosure.\nI:H - The stale pointer causes sctp_process_asconf_ack() to perform a second sctp_chunk_free() on an already-freed chunk, yielding a kmem_cache double-free that can be leveraged for arbitrary kernel write or control-flow hijack.\nA:H - Dereferencing the freed cached ASCONF chunk during ASCONF-ACK 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/associola.c", "net/sctp/sm_statefuns.c" ], "versions": [ { "version": "a000c01e60e40e15304ffe48fff051d17a7bea91", "lessThan": "10459b03e2d9ee12435e96f587de4d4cacdbf435", "status": "affected", "versionType": "git" }, { "version": "a000c01e60e40e15304ffe48fff051d17a7bea91", "lessThan": "e1bb114e09372fd6e03387ced9ef566da336ed6c", "status": "affected", "versionType": "git" }, { "version": "a000c01e60e40e15304ffe48fff051d17a7bea91", "lessThan": "179676f0166230c80053a392303485b37c93dd33", "status": "affected", "versionType": "git" }, { "version": "a000c01e60e40e15304ffe48fff051d17a7bea91", "lessThan": "dc67d528c2fa939cec7fe3bf7f3089c8d281ca3d", "status": "affected", "versionType": "git" }, { "version": "a000c01e60e40e15304ffe48fff051d17a7bea91", "lessThan": "618b5c6d049896fcfabb91afc072954c92cb2693", "status": "affected", "versionType": "git" }, { "version": "a000c01e60e40e15304ffe48fff051d17a7bea91", "lessThan": "07daf4f9750104960a1d60831b2353c0d41f35fb", "status": "affected", "versionType": "git" }, { "version": "a000c01e60e40e15304ffe48fff051d17a7bea91", "lessThan": "d949992bc3f00027a2c755e860a11950c75f6073", "status": "affected", "versionType": "git" }, { "version": "a000c01e60e40e15304ffe48fff051d17a7bea91", "lessThan": "8c283e7b56adce00193837f3311b06662466fb21", "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", "net/sctp/sm_statefuns.c" ], "versions": [ { "version": "3.0", "status": "affected" }, { "version": "0", "lessThan": "3.0", "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": "3.0", "versionEndExcluding": "5.10.265" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.0", "versionEndExcluding": "5.15.216" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.0", "versionEndExcluding": "6.1.183" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.0", "versionEndExcluding": "6.6.152" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.0", "versionEndExcluding": "6.12.104" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.0", "versionEndExcluding": "6.18.45" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.0", "versionEndExcluding": "7.1.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.0", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/10459b03e2d9ee12435e96f587de4d4cacdbf435" }, { "url": "https://git.kernel.org/stable/c/e1bb114e09372fd6e03387ced9ef566da336ed6c" }, { "url": "https://git.kernel.org/stable/c/179676f0166230c80053a392303485b37c93dd33" }, { "url": "https://git.kernel.org/stable/c/dc67d528c2fa939cec7fe3bf7f3089c8d281ca3d" }, { "url": "https://git.kernel.org/stable/c/618b5c6d049896fcfabb91afc072954c92cb2693" }, { "url": "https://git.kernel.org/stable/c/07daf4f9750104960a1d60831b2353c0d41f35fb" }, { "url": "https://git.kernel.org/stable/c/d949992bc3f00027a2c755e860a11950c75f6073" }, { "url": "https://git.kernel.org/stable/c/8c283e7b56adce00193837f3311b06662466fb21" } ], "title": "sctp: fix use-after-free of cached ASCONF chunk", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-74587", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "yes" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T19:01:25.161847Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:05:58.841Z" } } ] } }