CVE-2026-74667

CVE CVE-2026-74667EUVD EUVD-2026-64354Published 2026-08-22T15:32:38.000ZLast changed 2026-08-25T05:41:21.000ZCVSS 7.8

What the advisory describes

In the Linux kernel, the following vulnerability has been resolved: net/packet: reset the MAC header on the packet-socket transmit path packet_parse_headers() resets the MAC header only for a SOCK_RAW frame whose socket did not bind a protocol. A protocol-bound SOCK_RAW socket, any SOCK_DGRAM frame, and the legacy SOCK_PACKET path therefore leave skb->mac_header unset here. For frames sent via __dev_queue_xmit() this is harmless: it resets the MAC header unconditionally. But the packet-socket PACKET_QDISC_BYPASS path uses dev_direct_xmit(), which does not, so the frame reaches ndo_start_xmit() with the MAC header unset. A driver that reads eth_hdr(skb) on transmit then dereferences skb->head + (u16)~0, an out-of-bounds access ~64 KiB past the head -- the same class fixed for one consumer in commit f5089008f90c ("macsec: do not read an unset MAC header in macsec_encrypt()"). packet_parse_headers() runs only on the transmit path, where skb->data points at the start of the L2 header for every packet-socket type regardless of its length: SOCK_RAW and SOCK_PACKET carry a user-supplied header and SOCK_DGRAM has one built by dev_hard_header(). Reset the MAC header unconditionally, mirroring __dev_queue_xmit(), so the frame is anchored on the bypass path too. Found by 0sec (https://0sec.ai) using automated source analysis; verified against source and matched to the macsec KASAN report in f5089008f90c. Compile-tested.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

• Linux — Linux 75c65772c3d18447d62d3aca5f91b06c16cc25e4 <971aa7d99242bbf09513e27b7a243f0b29ff23ae; patch: 6.1.183; 75c65772c3d18447d62d3aca5f91b06c16cc25e4 <1e43a1d66615f411d427f9df1f46dd049d9e3681; 75c65772c3d18447d62d3aca5f91b06c16cc25e4 <b47ba8fe6e1d2df8c92048de5afafd059447dc30; patch: 5.10.265; 5.1; 75c65772c3d18447d62d3aca5f91b06c16cc25e4 <284f3e7a3f1a743fdf89e304fd1f19d5ffcff46d; 75c65772c3d18447d62d3aca5f91b06c16cc25e4 <4057853a91fb796c4f47c7d1baf1aa085394148e; patch: 0; patch: 7.1.9; patch: 6.18.45; patch: 7.2; 75c65772c3d18447d62d3aca5f91b06c16cc25e4 <2610ed4e86a4590234a9d70518c469751c5af231; patch: 6.12.104; patch: 6.6.152; 75c65772c3d18447d62d3aca5f91b06c16cc25e4 <c2707480cfbf19c7619acc9c089d17f20869821f; patch: 5.15.216; 75c65772c3d18447d62d3aca5f91b06c16cc25e4 <fdd4d7d52358a58e351dd9d82530c04eba8ccd7a

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

• Linux — Linux

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