{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74667","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-15T05:44:03.924Z","datePublished":"2026-08-22T15:32:38.862Z","dateUpdated":"2026-08-22T15:32:38.862Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-22T15:32:38.862Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/packet: reset the MAC header on the packet-socket transmit path\n\npacket_parse_headers() resets the MAC header only for a SOCK_RAW frame\nwhose socket did not bind a protocol. A protocol-bound SOCK_RAW socket,\nany SOCK_DGRAM frame, and the legacy SOCK_PACKET path therefore leave\nskb->mac_header unset here.\n\nFor frames sent via __dev_queue_xmit() this is harmless: it resets the\nMAC header unconditionally. But the packet-socket PACKET_QDISC_BYPASS\npath uses dev_direct_xmit(), which does not, so the frame reaches\nndo_start_xmit() with the MAC header unset. A driver that reads\neth_hdr(skb) on transmit then dereferences skb->head + (u16)~0, an\nout-of-bounds access ~64 KiB past the head -- the same class fixed for\none consumer in commit f5089008f90c (\"macsec: do not read an unset MAC\nheader in macsec_encrypt()\").\n\npacket_parse_headers() runs only on the transmit path, where skb->data\npoints at the start of the L2 header for every packet-socket type\nregardless of its length: SOCK_RAW and SOCK_PACKET carry a user-supplied\nheader and SOCK_DGRAM has one built by dev_hard_header(). Reset the MAC\nheader unconditionally, mirroring __dev_queue_xmit(), so the frame is\nanchored on the bypass path too.\n\nFound by 0sec (https://0sec.ai) using automated source analysis;\nverified against source and matched to the macsec KASAN report in\nf5089008f90c. Compile-tested."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/packet/af_packet.c"],"versions":[{"version":"75c65772c3d18447d62d3aca5f91b06c16cc25e4","lessThan":"1e43a1d66615f411d427f9df1f46dd049d9e3681","status":"affected","versionType":"git"},{"version":"75c65772c3d18447d62d3aca5f91b06c16cc25e4","lessThan":"4057853a91fb796c4f47c7d1baf1aa085394148e","status":"affected","versionType":"git"},{"version":"75c65772c3d18447d62d3aca5f91b06c16cc25e4","lessThan":"2610ed4e86a4590234a9d70518c469751c5af231","status":"affected","versionType":"git"},{"version":"75c65772c3d18447d62d3aca5f91b06c16cc25e4","lessThan":"b47ba8fe6e1d2df8c92048de5afafd059447dc30","status":"affected","versionType":"git"},{"version":"75c65772c3d18447d62d3aca5f91b06c16cc25e4","lessThan":"284f3e7a3f1a743fdf89e304fd1f19d5ffcff46d","status":"affected","versionType":"git"},{"version":"75c65772c3d18447d62d3aca5f91b06c16cc25e4","lessThan":"971aa7d99242bbf09513e27b7a243f0b29ff23ae","status":"affected","versionType":"git"},{"version":"75c65772c3d18447d62d3aca5f91b06c16cc25e4","lessThan":"fdd4d7d52358a58e351dd9d82530c04eba8ccd7a","status":"affected","versionType":"git"},{"version":"75c65772c3d18447d62d3aca5f91b06c16cc25e4","lessThan":"c2707480cfbf19c7619acc9c089d17f20869821f","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/packet/af_packet.c"],"versions":[{"version":"5.1","status":"affected"},{"version":"0","lessThan":"5.1","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":"5.1","versionEndExcluding":"5.10.265"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.1","versionEndExcluding":"5.15.216"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.1","versionEndExcluding":"6.1.183"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.1","versionEndExcluding":"6.6.152"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.1","versionEndExcluding":"6.12.104"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.1","versionEndExcluding":"6.18.45"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.1","versionEndExcluding":"7.1.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.1","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/1e43a1d66615f411d427f9df1f46dd049d9e3681"},{"url":"https://git.kernel.org/stable/c/4057853a91fb796c4f47c7d1baf1aa085394148e"},{"url":"https://git.kernel.org/stable/c/2610ed4e86a4590234a9d70518c469751c5af231"},{"url":"https://git.kernel.org/stable/c/b47ba8fe6e1d2df8c92048de5afafd059447dc30"},{"url":"https://git.kernel.org/stable/c/284f3e7a3f1a743fdf89e304fd1f19d5ffcff46d"},{"url":"https://git.kernel.org/stable/c/971aa7d99242bbf09513e27b7a243f0b29ff23ae"},{"url":"https://git.kernel.org/stable/c/fdd4d7d52358a58e351dd9d82530c04eba8ccd7a"},{"url":"https://git.kernel.org/stable/c/c2707480cfbf19c7619acc9c089d17f20869821f"}],"title":"net/packet: reset the MAC header on the packet-socket transmit path","x_generator":{"engine":"bippy-1.2.0"}}}}