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CVE-2026-74668

HIGHCVSS 7.8/10EPSS 0.13%

Last modified

CVE-2026-74668 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. 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. EPSS estimates a 0.13% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1
7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability
0.13%

2.3th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
LinuxLinux>= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1, < 9c7e8ff48c377bef18c3d178748aea0575b69ede; >= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1, < 2a73b2c37ee3060a880b53cd24783d93fc7be5f8; >= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1, < e79f59a8527a49078cfaf8fe8fb5fcefc20c76d2; >= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1, < d85d2fd54e901637c81d847811e03c662aee13cd; >= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1, < 016763e829cac37b3234eace86fd0a4c560de4a7; >= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1, < 27e068d1b35dbec10a3cf268887c94407be4badc; >= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1, < d48ea5c9c4c34dc0df621f0e39ed3a16b644621a; >= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1, < 21b5953e7494c16a42e6cd8cf110e18d13ae4a6b
LinuxLinux2.6.31

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is 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.
How severe is CVE-2026-74668?
CVE-2026-74668 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.13% probability of exploitation in the next 30 days.
How do I fix CVE-2026-74668?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST