{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89477", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.711Z", "datePublished": "2026-09-11T19:43:33.851Z", "dateUpdated": "2026-10-19T08:47:26.175Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:47:26.175Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: fix NULL deref on untransmitted RECONF completion\n\nsctp_process_strreset_outreq(), sctp_process_strreset_addstrm_out() and\nsctp_process_strreset_resp() complete a pending stream reconfiguration\nrequest by stopping the reconf timer on the transport it was sent on:\n\n\tt = asoc->strreset_chunk->transport;\n\tif (timer_delete(&t->reconf_timer))\n\t\tsctp_transport_put(t);\n\nchunk->transport is assigned by __sctp_packet_append_chunk() when the\nchunk is appended to an outbound packet, and sctp_outq_flush_ctrl() arms\nthe reconf timer at that same point. A request already published in\nasoc->strreset_chunk but not yet transmitted has neither, so completing\nit dereferences NULL.\n\nTwo ways to get there. sctp_send_asconf_del_ip() sets\nasoc->src_out_of_asoc_ok without sending anything when the address being\nremoved is the association's last one, and sctp_outq_flush_ctrl() then\nleaves every non-ASCONF control chunk queued; as only\nsctp_process_asconf_ack() clears that flag, it persists. An unprivileged\nprocess that removes such an address and then asks for a stream reset\npanics the kernel from softirq. A peer needs neither ASCONF nor local\nhelp: sctp_cmd_interpreter() uncorks the outqueue only once the whole\npacket has been processed, so a reply built while walking a RECONF chunk\nstays untransmitted for the rest of that walk, and one RECONF chunk\ncarrying [Incoming SSN Reset Request, Outgoing SSN Reset Request,\nResponse] -- or two RECONF chunks in one packet -- reaches the same\ndereference.\n\n KASAN: null-ptr-deref in range [0x00000000000001e8-0x00000000000001ef]\n RIP: 0010:timer_delete+0x67/0x110\n Call Trace:\n \n sctp_process_strreset_addstrm_out (net/sctp/stream.c:832)\n sctp_sf_do_reconf (net/sctp/sm_statefuns.c:4212)\n sctp_do_sm (net/sctp/sm_sideeffect.c:1172)\n sctp_assoc_bh_rcv (net/sctp/associola.c:1044)\n sctp_rcv (net/sctp/input.c:243)\n ip_local_deliver (net/ipv4/ip_input.c:262)\n process_backlog (net/core/dev.c:6680)\n \n\nA response can only acknowledge a request that was actually sent, so do\nnot match asoc->strreset_chunk while chunk->transport is NULL. Guarding\nthe lookup covers all three completion sites." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - A remote SCTP peer reaches the bug via sctp_rcv() -> sctp_assoc_bh_rcv() -> sctp_sf_do_reconf() on an established association; one RECONF carrying Incoming/Outgoing SSN Reset plus Response, or two bundled RECONF chunks, completes an untransmitted strreset_chunk. This is internet-facing SCTP (telecom/Diameter), not a local-only syscall.\nAC:L - The attacker fully controls the packet: sctp_cmd_interpreter() keeps the outqueue corked until the whole packet is processed, so the generated RECONF reply stays untransmitted and the follow-on parameter/chunk deterministically NULL-dereferences. request_seq is the peer's initial TSN from INIT/INIT-ACK; no race or uninfluenceable memory layout is required.\nPR:N - Triggering requires only a network-reachable established SCTP association; the attacker needs no local account, capabilities, or namespaces on the victim. RECONF is processed in ESTABLISHED without SCTP-AUTH by default (empty auth chunk list), so no extra credentials beyond being the SCTP peer.\nUI:N - Exploitation is driven entirely by inbound SCTP packets processed automatically in softirq on a listening or already-associated endpoint; no victim user action such as opening a file or mounting a filesystem is required.\nS:U - Impact is a kernel NULL dereference and oops in the host SCTP stack, remaining in the same kernel security authority; it is not a VM/guest-to-host escape, IOMMU bypass, or other cross-boundary breakout.\nC:N - The defect is a pure NULL pointer dereference of strreset_chunk->transport in timer_delete() (KASAN range around offset 0x1e8). No out-of-bounds read, UAF object reuse, or other disclosure primitive is involved.\nI:N - Only a NULL transport pointer is loaded and passed to timer_delete(); there is no write, type confusion, or memory corruption that could hijack control flow or modify kernel state beyond the crash.\nA:H - timer_delete() on the NULL transport oopses/panics the kernel from SCTP receive softirq (documented KASAN null-ptr-deref in sctp_process_strreset_*), which is a full availability loss and can be repeated at will by the peer." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sctp/stream.c" ], "versions": [ { "version": "81054476453640159149cb6704e834893e16736b", "lessThan": "79ff751311e80fa0370007e46a79a6d601685e75", "status": "affected", "versionType": "git" }, { "version": "81054476453640159149cb6704e834893e16736b", "lessThan": "53141db979687eae7dc6d29414cefc77034f967e", "status": "affected", "versionType": "git" }, { "version": "81054476453640159149cb6704e834893e16736b", "lessThan": "68891125af5a5dfbca728809a16637a869bbe0df", "status": "affected", "versionType": "git" }, { "version": "81054476453640159149cb6704e834893e16736b", "lessThan": "b2d6d873b4dfb5b84194061c4b40a1cd85b92ca4", "status": "affected", "versionType": "git" }, { "version": "81054476453640159149cb6704e834893e16736b", "lessThan": "77ea60f2d24002c308f224db44a4542c466489af", "status": "affected", "versionType": "git" }, { "version": "81054476453640159149cb6704e834893e16736b", "lessThan": "25419f516ea84b1e7d3d55aae5215ac86ece0c66", "status": "affected", "versionType": "git" }, { "version": "81054476453640159149cb6704e834893e16736b", "lessThan": "0ee697defc0594f1da810ed75d9d643fb46f5318", "status": "affected", "versionType": "git" }, { "version": "81054476453640159149cb6704e834893e16736b", "lessThan": "2db9bfa3e27bdea15e05ea70b56bad3d21e570ec", "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/stream.c" ], "versions": [ { "version": "4.11", "status": "affected" }, { "version": "0", "lessThan": "4.11", "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": "4.11", "versionEndExcluding": "5.10.270" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "6.12.109" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "6.18.50" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "7.2.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.11", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/79ff751311e80fa0370007e46a79a6d601685e75" }, { "url": "https://git.kernel.org/stable/c/53141db979687eae7dc6d29414cefc77034f967e" }, { "url": "https://git.kernel.org/stable/c/68891125af5a5dfbca728809a16637a869bbe0df" }, { "url": "https://git.kernel.org/stable/c/b2d6d873b4dfb5b84194061c4b40a1cd85b92ca4" }, { "url": "https://git.kernel.org/stable/c/77ea60f2d24002c308f224db44a4542c466489af" }, { "url": "https://git.kernel.org/stable/c/25419f516ea84b1e7d3d55aae5215ac86ece0c66" }, { "url": "https://git.kernel.org/stable/c/0ee697defc0594f1da810ed75d9d643fb46f5318" }, { "url": "https://git.kernel.org/stable/c/2db9bfa3e27bdea15e05ea70b56bad3d21e570ec" } ], "title": "sctp: fix NULL deref on untransmitted RECONF completion", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-89477", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "yes" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2026-10-16T19:22:22.091820Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:26:39.087Z" } } ] } }