{"id":"CVE-2026-68161","state":"PUBLISHED","title":"sctp: close UDP tunnel sockets during netns teardown","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: close UDP tunnel sockets during netns teardown\n\nproc_sctp_do_udp_port() starts per-net SCTP UDP tunneling sockets when\nnet.sctp.udp_port is set, and stops/restarts them when the sysctl value\nchanges. The netns exit path does not stop these sockets, so a namespace\ncan be torn down while its SCTP UDP tunnel sockets are still installed.\n\nClose the UDP tunnel sockets from sctp_ctrlsock_exit() after unregistering\nthe per-net sysctl table. This prevents new sysctl writes from racing in\nwhile the sockets are being released, and closes the sockets before the\ncontrol socket is destroyed.","publishedAt":"2026-08-10T11:59:28.072Z","updatedAt":"2026-10-19T20:58:55.541Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"046c052b475e7119b6a30e3483e2888fc606a2f8","status":"affected","lessThan":"c29affd44e6769e3073235d4b471d9b501fa8166","versionType":"git"},{"version":"046c052b475e7119b6a30e3483e2888fc606a2f8","status":"affected","lessThan":"c6eb2d615210b80339548ab07c0230edaab9a6c7","versionType":"git"},{"version":"046c052b475e7119b6a30e3483e2888fc606a2f8","status":"affected","lessThan":"8ff78591d309c50a4fdab683b68dd8d512a270dd","versionType":"git"},{"version":"046c052b475e7119b6a30e3483e2888fc606a2f8","status":"affected","lessThan":"3bf0e349cbb4f975f35eb22753acc346b89c66a0","versionType":"git"},{"version":"046c052b475e7119b6a30e3483e2888fc606a2f8","status":"affected","lessThan":"37ff9794be48d0caa37687e04d09675f9c849121","versionType":"git"},{"version":"046c052b475e7119b6a30e3483e2888fc606a2f8","status":"affected","lessThan":"ffb2bd7ade36ec4da32c46a6eddbf4515316d08c","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sctp/protocol.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.11","versionType":"semver"},{"version":"6.1.189","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.151","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.101","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.42","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sctp/protocol.c"]}],"references":["https://git.kernel.org/stable/c/c29affd44e6769e3073235d4b471d9b501fa8166","https://git.kernel.org/stable/c/c6eb2d615210b80339548ab07c0230edaab9a6c7","https://git.kernel.org/stable/c/8ff78591d309c50a4fdab683b68dd8d512a270dd","https://git.kernel.org/stable/c/3bf0e349cbb4f975f35eb22753acc346b89c66a0","https://git.kernel.org/stable/c/37ff9794be48d0caa37687e04d09675f9c849121","https://git.kernel.org/stable/c/ffb2bd7ade36ec4da32c46a6eddbf4515316d08c"],"weaknesses":["CWE-404"],"ingestedAt":"2026-10-29T20:12:49.727Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/68xxx/CVE-2026-68161.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-68161","state":"PUBLISHED","datePublished":"2026-08-10T11:59:28.072Z","dateUpdated":"2026-10-19T20:58:55.541Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-30T09:28:09.372Z"},"containers":{"cna":{"title":"sctp: close UDP tunnel sockets during netns teardown","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: close UDP tunnel sockets during netns teardown\n\nproc_sctp_do_udp_port() starts per-net SCTP UDP tunneling sockets when\nnet.sctp.udp_port is set, and stops/restarts them when the sysctl value\nchanges. The netns exit path does not stop these sockets, so a namespace\ncan be torn down while its SCTP UDP tunnel sockets are still installed.\n\nClose the UDP tunnel sockets from sctp_ctrlsock_exit() after unregistering\nthe per-net sysctl table. This prevents new sysctl writes from racing in\nwhile the sockets are being released, and closes the sockets before the\ncontrol socket is destroyed."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"046c052b475e7119b6a30e3483e2888fc606a2f8","status":"affected","lessThan":"c29affd44e6769e3073235d4b471d9b501fa8166","versionType":"git"},{"version":"046c052b475e7119b6a30e3483e2888fc606a2f8","status":"affected","lessThan":"c6eb2d615210b80339548ab07c0230edaab9a6c7","versionType":"git"},{"version":"046c052b475e7119b6a30e3483e2888fc606a2f8","status":"affected","lessThan":"8ff78591d309c50a4fdab683b68dd8d512a270dd","versionType":"git"},{"version":"046c052b475e7119b6a30e3483e2888fc606a2f8","status":"affected","lessThan":"3bf0e349cbb4f975f35eb22753acc346b89c66a0","versionType":"git"},{"version":"046c052b475e7119b6a30e3483e2888fc606a2f8","status":"affected","lessThan":"37ff9794be48d0caa37687e04d09675f9c849121","versionType":"git"},{"version":"046c052b475e7119b6a30e3483e2888fc606a2f8","status":"affected","lessThan":"ffb2bd7ade36ec4da32c46a6eddbf4515316d08c","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sctp/protocol.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.11","versionType":"semver"},{"version":"6.1.189","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.151","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.101","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.42","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sctp/protocol.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/c29affd44e6769e3073235d4b471d9b501fa8166"},{"url":"https://git.kernel.org/stable/c/c6eb2d615210b80339548ab07c0230edaab9a6c7"},{"url":"https://git.kernel.org/stable/c/8ff78591d309c50a4fdab683b68dd8d512a270dd"},{"url":"https://git.kernel.org/stable/c/3bf0e349cbb4f975f35eb22753acc346b89c66a0"},{"url":"https://git.kernel.org/stable/c/37ff9794be48d0caa37687e04d09675f9c849121"},{"url":"https://git.kernel.org/stable/c/ffb2bd7ade36ec4da32c46a6eddbf4515316d08c"}],"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 - Stale SCTP UDP tunnel sockets left installed after netns teardown still receive remote SCTP-over-UDP (RFC 6951) on the configured net.sctp.udp_port; packets enter sctp_udp_rcv→sctp_rcv in softirq and touch freed per-net SCTP/UDP state.\nAC:L - An attacker can repeatedly race namespace deletion against SCTP-over-UDP traffic they send or receive, controlling both teardown timing and packet delivery; no attacker-uncontrollable memory layout or rare kernel config is required beyond SCTP being enabled.\nPR:N - On SCTP-over-UDP deployments where net.sctp.udp_port is already configured, any remote SCTP peer needs no credentials on the target; alternatively an unprivileged local user obtains CAP_NET_ADMIN via user namespaces to set udp_port and destroy the namespace.\nUI:N - Exploitation requires only attacker-driven SCTP-over-UDP traffic and namespace lifecycle events (e.g., container restart); no victim must mount a filesystem, open a file, or take any separate interactive action.\nS:U - Impact is host-kernel slab use-after-free and memory corruption within the same OS security authority; it does not cross VM, IOMMU, or sandbox boundaries to affect a separate security domain.\nC:H - Use-after-free of struct net and SCTP UDP tunnel socket state lets an attacker influence freed slab contents and obtain arbitrary kernel memory read primitives through subsequent SCTP/UDP lookups and socket processing.\nI:H - The UAF enables heap grooming and reuse of freed per-net/socket objects in SCTP/UDP handlers, supporting arbitrary kernel writes and control-flow hijack typical of slab use-after-free exploitation.\nA:H - Dereferencing SCTP/UDP tunnel sockets and per-net state after netns free causes slab use-after-free detections, kernel oops, or panic; even unexploited UAF commonly crashes or hangs the host."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-03T10:55:39.636Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.1.189"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.6.151"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.12.101"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.18.42"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"7.1.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-68161","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:45:23.310568Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-404","lang":"en","type":"CWE","description":"CWE-404 Improper Resource Shutdown or Release"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:58:55.541Z"}}]}}}