Answer in brief
CVE-2026-74667 records a High severity (CVSS 7.8) vulnerability in net/packet: reset the MAC header on the packet-socket transmit path. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <1e43a1d66615f411d427f9df1f46dd049d9e3681 || >=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <4057853a91fb796c4f47c7d1baf1aa085394148e || >=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <2610ed4e86a4590234a9d70518c469751c5af231 || >=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <b47ba8fe6e1d2df8c92048de5afafd059447dc30 || >=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <284f3e7a3f1a743fdf89e304fd1f19d5ffcff46d || >=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <971aa7d99242bbf09513e27b7a243f0b29ff23ae || >=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <fdd4d7d52358a58e351dd9d82530c04eba8ccd7a || >=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <c2707480cfbf19c7619acc9c089d17f20869821f | 1e43a1d66615f411d427f9df1f46dd049d9e3681, 4057853a91fb796c4f47c7d1baf1aa085394148e, 2610ed4e86a4590234a9d70518c469751c5af231, b47ba8fe6e1d2df8c92048de5afafd059447dc30, 284f3e7a3f1a743fdf89e304fd1f19d5ffcff46d, 971aa7d99242bbf09513e27b7a243f0b29ff23ae, fdd4d7d52358a58e351dd9d82530c04eba8ccd7a, c2707480cfbf19c7619acc9c089d17f20869821f |
| Linux/Linuxgeneric | 5.1 | Not reported |
Published upstream
Aug 22, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 22, 2026
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.
Quoted source text, attributed separately from HOL analysis.