{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89478", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.711Z", "datePublished": "2026-09-11T19:43:34.588Z", "dateUpdated": "2026-10-19T08:47:27.202Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:47:27.202Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: drop a chunk if its transport was removed\n\nsctp_rcv() resolves the transport once per packet and leaves it in\nchunk->transport. The lookup reference, or the one sctp_add_backlog() takes\nif the socket is owned by userspace, keeps it around until the chunk has\nbeen processed.\n\nAn authenticated ASCONF DEL-IP can remove it in the meantime.\nsctp_assoc_rm_peer() takes the transport out of the association and calls\nsctp_transport_free(), which tags it dead and drops the reference the\nassociation held. There is a window on both paths: the packet can sit on\nthe socket backlog, and on the direct path the lookup completes before\nbh_lock_sock().\n\nThe DATA chunk in that packet puts the removed transport back into\nasoc->peer.last_data_from. Once the packet is done that reference goes\naway and the transport is freed by RCU, so the next delayed SACK carries\nthe pointer into the SACK chunk and sctp_outq_select_transport() reads the\nfreed transport's state.\n\nDrop the chunk in sctp_inq_push(), next to the existing rcvr->dead check.\nBoth paths reach it with the association's socket lock held. The peer\nretransmits it." } ], "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 - A remote SCTP peer reaches the bug via received packets in sctp_rcv() on internet-facing SCTP servers and telecom endpoints; DATA that already resolved a transport is processed after an authenticated ASCONF DEL-IP (or COOKIE-ECHO restart) has removed that peer.\nAC:L - The attacker controls both sides of the race by sending ASCONF DEL-IP (or a restart that calls sctp_assoc_rm_peer) and a DATA chunk whose lookup already holds the doomed transport; the backlog path is FIFO-deterministic while the socket is in a syscall, and the direct path is a bh_lock_sock race the attacker creates.\nPR:N - Exploitation requires only a network-reachable established SCTP association; no local Linux credentials, capabilities, or namespaces are needed, and SCTP-AUTH keys used for ASCONF come from the handshake the peer itself performs.\nUI:N - Inbound SCTP packets are processed automatically in softirq or socket backlog on a listening or already-associated endpoint; no victim user action such as opening a file or mounting a device is required.\nS:U - Impact is kernel memory corruption and potential privilege escalation within the host SCTP stack; it does not cross a VM, IOMMU, or other security-authority boundary.\nC:H - DATA processing plants the removed transport into asoc->peer.last_data_from; after the lookup reference is dropped the object is RCU-freed, and the next delayed SACK dereferences the freed sctp_transport in sctp_outq_select_transport(), a UAF that enables arbitrary kernel disclosure via heap grooming.\nI:H - sctp_outq_select_transport() does list_add_tail() into the freed send_ready field, and sctp_packet_config()/sctp_transport_burst_limited() write vtag, pathmtu, cwnd, and burst_limited into the reclaimed slab object, yielding arbitrary write and control-flow hijack primitives.\nA:H - Dereferencing the freed transport during delayed SACK transmission can immediately oops or panic the kernel, and the UAF can be triggered repeatedly by a malicious SCTP peer." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sctp/inqueue.c" ], "versions": [ { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "3fc072e7cb4a0ff251d13cfc2d24f62489cd9386", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "d7cb5ad832095dc4becfdb2a36007ffd50e49fb0", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "0422b092a3d43ca462932ff9f747731ca078d1d4", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "928fd7920ba37cc5637a211b9be979083413a2fa", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "c6c86a5e62a4fec36692ddd64b9144b660f71f96", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "1035bdef1efb9b1076d1a57b81e08c637ff08ecc", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "3537961df2163258bddc230db0e18dc14e925ea6", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "03a9d10ecf71f54b2af8020935f2033d4a132be5", "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/inqueue.c" ], "versions": [ { "version": "2.6.12", "status": "affected" }, { "version": "0", "lessThan": "2.6.12", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.270", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.221", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.109", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "5.10.270" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.12.109" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.18.50" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "7.2.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/3fc072e7cb4a0ff251d13cfc2d24f62489cd9386" }, { "url": "https://git.kernel.org/stable/c/d7cb5ad832095dc4becfdb2a36007ffd50e49fb0" }, { "url": "https://git.kernel.org/stable/c/0422b092a3d43ca462932ff9f747731ca078d1d4" }, { "url": "https://git.kernel.org/stable/c/928fd7920ba37cc5637a211b9be979083413a2fa" }, { "url": "https://git.kernel.org/stable/c/c6c86a5e62a4fec36692ddd64b9144b660f71f96" }, { "url": "https://git.kernel.org/stable/c/1035bdef1efb9b1076d1a57b81e08c637ff08ecc" }, { "url": "https://git.kernel.org/stable/c/3537961df2163258bddc230db0e18dc14e925ea6" }, { "url": "https://git.kernel.org/stable/c/03a9d10ecf71f54b2af8020935f2033d4a132be5" } ], "title": "sctp: drop a chunk if its transport was removed", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-89478", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "yes" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T19:22:25.085426Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:26:39.233Z" } } ] } }