{"id":"CVE-2026-43373","state":"PUBLISHED","title":"net: ncsi: fix skb leak in error paths","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ncsi: fix skb leak in error paths\n\nEarly return paths in NCSI RX and AEN handlers fail to release\nthe received skb, resulting in a memory leak.\n\nSpecifically, ncsi_aen_handler() returns on invalid AEN packets\nwithout consuming the skb. Similarly, ncsi_rcv_rsp() exits early\nwhen failing to resolve the NCSI device, response handler, or\nrequest, leaving the skb unfreed.","publishedAt":"2026-05-08T14:21:23.875Z","updatedAt":"2026-08-05T12:27:33.592Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"138635cc27c9737f940c3aa80912ff7a61c825af","status":"affected","lessThan":"9891d7f4f1ede473c54b49776ae07755083eef06","versionType":"git"},{"version":"138635cc27c9737f940c3aa80912ff7a61c825af","status":"affected","lessThan":"fef5aa6e3bcf3c8053307642663a63b7362d7552","versionType":"git"},{"version":"138635cc27c9737f940c3aa80912ff7a61c825af","status":"affected","lessThan":"81d6aee32f8f7bbc175c05dbf61f4430bfb88c4a","versionType":"git"},{"version":"138635cc27c9737f940c3aa80912ff7a61c825af","status":"affected","lessThan":"59962588197863d0d746879f193905c0c6b3df49","versionType":"git"},{"version":"138635cc27c9737f940c3aa80912ff7a61c825af","status":"affected","lessThan":"553366c271479c0d571dd1bb5d1bcde4747fb82e","versionType":"git"},{"version":"138635cc27c9737f940c3aa80912ff7a61c825af","status":"affected","lessThan":"b70c4e5e711931cdd56e6e905737b72f1e649189","versionType":"git"},{"version":"138635cc27c9737f940c3aa80912ff7a61c825af","status":"affected","lessThan":"87138dde2d6937b12b967f28fe598a7d59000ae4","versionType":"git"},{"version":"138635cc27c9737f940c3aa80912ff7a61c825af","status":"affected","lessThan":"5c3398a54266541610c8d0a7082e654e9ff3e259","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ncsi/ncsi-aen.c","net/ncsi/ncsi-rsp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.8","versionType":"semver"},{"version":"5.10.253","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.203","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.167","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.130","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.78","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.19","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.9","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ncsi/ncsi-aen.c","net/ncsi/ncsi-rsp.c"]}],"references":["https://git.kernel.org/stable/c/9891d7f4f1ede473c54b49776ae07755083eef06","https://git.kernel.org/stable/c/fef5aa6e3bcf3c8053307642663a63b7362d7552","https://git.kernel.org/stable/c/81d6aee32f8f7bbc175c05dbf61f4430bfb88c4a","https://git.kernel.org/stable/c/59962588197863d0d746879f193905c0c6b3df49","https://git.kernel.org/stable/c/553366c271479c0d571dd1bb5d1bcde4747fb82e","https://git.kernel.org/stable/c/b70c4e5e711931cdd56e6e905737b72f1e649189","https://git.kernel.org/stable/c/87138dde2d6937b12b967f28fe598a7d59000ae4","https://git.kernel.org/stable/c/5c3398a54266541610c8d0a7082e654e9ff3e259"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/43xxx/CVE-2026-43373.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-43373","state":"PUBLISHED","datePublished":"2026-05-08T14:21:23.875Z","dateUpdated":"2026-08-05T12:27:33.592Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-01T14:12:56.006Z"},"containers":{"cna":{"title":"net: ncsi: fix skb leak in error paths","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ncsi: fix skb leak in error paths\n\nEarly return paths in NCSI RX and AEN handlers fail to release\nthe received skb, resulting in a memory leak.\n\nSpecifically, ncsi_aen_handler() returns on invalid AEN packets\nwithout consuming the skb. Similarly, ncsi_rcv_rsp() exits early\nwhen failing to resolve the NCSI device, response handler, or\nrequest, leaving the skb unfreed."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"138635cc27c9737f940c3aa80912ff7a61c825af","status":"affected","lessThan":"9891d7f4f1ede473c54b49776ae07755083eef06","versionType":"git"},{"version":"138635cc27c9737f940c3aa80912ff7a61c825af","status":"affected","lessThan":"fef5aa6e3bcf3c8053307642663a63b7362d7552","versionType":"git"},{"version":"138635cc27c9737f940c3aa80912ff7a61c825af","status":"affected","lessThan":"81d6aee32f8f7bbc175c05dbf61f4430bfb88c4a","versionType":"git"},{"version":"138635cc27c9737f940c3aa80912ff7a61c825af","status":"affected","lessThan":"59962588197863d0d746879f193905c0c6b3df49","versionType":"git"},{"version":"138635cc27c9737f940c3aa80912ff7a61c825af","status":"affected","lessThan":"553366c271479c0d571dd1bb5d1bcde4747fb82e","versionType":"git"},{"version":"138635cc27c9737f940c3aa80912ff7a61c825af","status":"affected","lessThan":"b70c4e5e711931cdd56e6e905737b72f1e649189","versionType":"git"},{"version":"138635cc27c9737f940c3aa80912ff7a61c825af","status":"affected","lessThan":"87138dde2d6937b12b967f28fe598a7d59000ae4","versionType":"git"},{"version":"138635cc27c9737f940c3aa80912ff7a61c825af","status":"affected","lessThan":"5c3398a54266541610c8d0a7082e654e9ff3e259","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ncsi/ncsi-aen.c","net/ncsi/ncsi-rsp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.8","versionType":"semver"},{"version":"5.10.253","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.203","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.167","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.130","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.78","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.19","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.9","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ncsi/ncsi-aen.c","net/ncsi/ncsi-rsp.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/9891d7f4f1ede473c54b49776ae07755083eef06"},{"url":"https://git.kernel.org/stable/c/fef5aa6e3bcf3c8053307642663a63b7362d7552"},{"url":"https://git.kernel.org/stable/c/81d6aee32f8f7bbc175c05dbf61f4430bfb88c4a"},{"url":"https://git.kernel.org/stable/c/59962588197863d0d746879f193905c0c6b3df49"},{"url":"https://git.kernel.org/stable/c/553366c271479c0d571dd1bb5d1bcde4747fb82e"},{"url":"https://git.kernel.org/stable/c/b70c4e5e711931cdd56e6e905737b72f1e649189"},{"url":"https://git.kernel.org/stable/c/87138dde2d6937b12b967f28fe598a7d59000ae4"},{"url":"https://git.kernel.org/stable/c/5c3398a54266541610c8d0a7082e654e9ff3e259"}],"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 - The vulnerable handlers are reached through the kernel Ethernet receive path for ETH_P_NCSI frames on an NCSI-enabled network device. A remote peer capable of delivering NCSI frames to the management interface can trigger the bug with network packets.\nAC:L - Triggering only requires malformed or unmatched NCSI response/AEN packets that take deterministic early error paths. No race, timing, or hard-to-control system state is required.\nPR:N - The packet receive path performs no credential, capability, or authentication checks before entering ncsi_rcv_rsp() or ncsi_aen_handler(). Local NCSI netlink operations may require admin permission, but the vulnerable receive path does not.\nUI:N - No victim user action is needed. Packets are processed automatically by the network receive stack.\nS:U - The impact remains within the kernel and the affected NCSI/network device security authority. There is no VM, sandbox, IOMMU, or other cross-scope boundary crossing.\nC:N - The fixed bug is a missing kfree_skb()/consume_skb() on error paths, not an information disclosure. The leaked skb is not exposed back to the attacker.\nI:N - The bug does not corrupt memory or provide a write primitive. It only retains references to received skb objects that should have been freed.\nA:H - Each trigger leaks a received skb, and the attacker can repeat this indefinitely with malformed or unmatched NCSI packets. On plausible BMC/management-controller deployments this can exhaust kernel memory and deny service."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:27:33.592Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"5.10.253"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"5.15.203"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"6.1.167"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"6.6.130"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"6.12.78"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"6.18.19"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"6.19.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}