CVE-2026-74668: Linux

High severity, CVSS 7.8. EPSS: 0.1% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: packet: use consistent hard_header_len in TX_RING send path tpacket_snd() reads dev->hard_header_len independently for skb allocation and header construction in tpacket_fill_skb(). Concurrent netdevice reconfiguration can therefore make the reserved headroom smaller than the amount later pushed, or make copylen - hard_header_len negative. Snapshot hard_header_len once before processing ring frames and use it for the frame limit, headroom allocation, copy length, and skb construction. Pass the snapshot to tpacket_fill_skb(). The separate SOCK_DGRAM consistency problem between hard_header_len and header_ops->create is not addressed here.

Affected products

• Linux Linux: from 2.6.31, before 5.10.267 (fixed in 5.10.267); from 5.11, before 5.15.218 (fixed in 5.15.218); from 5.16, before 6.1.185 (fixed in 6.1.185); from 6.2, before 6.6.152 (fixed in 6.6.152); from 6.7, before 6.12.104 (fixed in 6.12.104); from 6.13, before 6.18.45 (fixed in 6.18.45); …

Published 2026-08-22. Last modified 2026-08-27.