{"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": "2026-08-25T05:40:13.798Z"}, "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\u2014establishing 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\u2014without 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"}}}}

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/sctp/associola.c", "net/sctp/sm_statefuns.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "10459b03e2d9ee12435e96f587de4d4cacdbf435", "status": "affected", "version": "a000c01e60e40e15304ffe48fff051d17a7bea91", "versionType": "git"}, {"lessThan": "e1bb114e09372fd6e03387ced9ef566da336ed6c", "status": "affected", "version": "a000c01e60e40e15304ffe48fff051d17a7bea91", "versionType": "git"}, {"lessThan": "179676f0166230c80053a392303485b37c93dd33", "status": "affected", "version": "a000c01e60e40e15304ffe48fff051d17a7bea91", "versionType": "git"}, {"lessThan": "dc67d528c2fa939cec7fe3bf7f3089c8d281ca3d", "status": "affected", "version": "a000c01e60e40e15304ffe48fff051d17a7bea91", "versionType": "git"}, {"lessThan": "618b5c6d049896fcfabb91afc072954c92cb2693", "status": "affected", "version": "a000c01e60e40e15304ffe48fff051d17a7bea91", "versionType": "git"}, {"lessThan": "07daf4f9750104960a1d60831b2353c0d41f35fb", "status": "affected", "version": "a000c01e60e40e15304ffe48fff051d17a7bea91", "versionType": "git"}, {"lessThan": "d949992bc3f00027a2c755e860a11950c75f6073", "status": "affected", "version": "a000c01e60e40e15304ffe48fff051d17a7bea91", "versionType": "git"}, {"lessThan": "8c283e7b56adce00193837f3311b06662466fb21", "status": "affected", "version": "a000c01e60e40e15304ffe48fff051d17a7bea91", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/sctp/associola.c", "net/sctp/sm_statefuns.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "3.0"}, {"lessThan": "3.0", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.10.*", "status": "unaffected", "version": "5.10.265", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.216", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.183", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.152", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.104", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.45", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.9", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "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."}], "id": "CVE-2026-74587", "lastModified": "2026-08-25T06:18:33.087", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.8, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-08-22T16:16:30.830", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/07daf4f9750104960a1d60831b2353c0d41f35fb"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/10459b03e2d9ee12435e96f587de4d4cacdbf435"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/179676f0166230c80053a392303485b37c93dd33"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/618b5c6d049896fcfabb91afc072954c92cb2693"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/8c283e7b56adce00193837f3311b06662466fb21"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d949992bc3f00027a2c755e860a11950c75f6073"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/dc67d528c2fa939cec7fe3bf7f3089c8d281ca3d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e1bb114e09372fd6e03387ced9ef566da336ed6c"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: sctp: fix use-after-free of cached ASCONF chunk", "id": "2521434", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2521434"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-825", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nsctp: fix use-after-free of cached ASCONF chunk\naddip_last_asconf caches the outstanding outbound ASCONF chunk. The normal\nASCONF-ACK completion path releases the chunk and clears the pointer.\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.\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.\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.\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.", "A flaw was found in the Linux kernel's Stream Control Transmission Protocol (SCTP) implementation. During peer restart handling, the system improperly releases a cached ASCONF chunk without clearing its pointer, leading to a use-after-free vulnerability. A remote attacker could exploit this by sending a delayed authenticated ASCONF-ACK, causing the system to access freed memory. This could result in a system crash, leading to a denial of service."], "name": "CVE-2026-74587", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Under investigation", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-22T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-74587\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-74587\nhttps://lore.kernel.org/linux-cve-announce/2026082212-CVE-2026-74587-d6f8@gregkh/T"], "threat_severity": "Moderate"}