CVE-2026-74668
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 versions
Linux kernel versions
2.6.31
and later are affected. Fixed in
6.6.152,
6.12.104,
6.18.45,
7.1.9,
7.2
and their respective stable series.
References
5 totalFrequently asked questions
-
What is CVE-2026-74668?
CVE-2026-74668 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 2.6.31 onward and has been patched in 6.6.152, 6.12.104, 6.18.45 and others. CVE-2026-74668 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
-
Is there a patch available for CVE-2026-74668?
Yes. CVE-2026-74668 has been patched. Fixed versions include 6.6.152, 6.12.104, 6.18.45 and others. If you are running Linux kernel 2.6.31 or later up to the fix versions, apply the relevant patch for your kernel branch.
-
Is CVE-2026-74668 actively exploited?
No. CVE-2026-74668 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.