PT-2026-61324 · Linux · Linux Kernel

CVE-2026-64007 · Published 2026-07-19 · Updated 2026-07-19

Positive Technologies (AI Summary)

CVSS v3.1

9.8

Critical

Base vector

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

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An issue exists in the netfilter synproxy component where the synproxy tstamp adjust() function fails to refresh the TCP header pointer after calling skb ensure writable(). When skb ensure writable() is invoked on a cloned or non-linear socket buffer (skb), it may trigger pskb expand head(), which frees the original memory location of the header. Because the function continues to use a stale pointer for the TCP checksum update via inet proto csum replace4(), it may result in a write operation into freed slab memory or cause packets to be sent with an incorrect checksum that does not match the payload.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Related Identifiers

CVE-2026-64007

Affected Products

Linux Kernel

References · 11

• https://nvd.nist.gov/vuln/detail/CVE-2026-64007 · Security Note
• https://git.kernel.org/stable/c/af2c22ccb1f621aff487ff47a040e38e058541e7 · Note
• https://git.kernel.org/stable/c/92170e6afe927ab2792a3f71902845789c8e31b1 · Note
• https://git.kernel.org/stable/c/a91887a5b6ee4b98dfbf1db657ed2b879430149e · Note
• https://git.kernel.org/stable/c/f0fea2b6d5453a11ad11713bbf37561b9b3a7edf · Note
• https://git.kernel.org/stable/c/dd206819f210522579010d889d45a9530bb494bc · Note
• https://twitter.com/CVEnew/status/2078861427956208047 · Twitter Post
• https://git.kernel.org/stable/c/9902a1058992de5d95656b64a3bd95c077f7ba2c · Note
• https://git.kernel.org/stable/c/d3019c61799adc21811af4b521f11f3dc77f8e04 · Note
• https://git.kernel.org/stable/c/c7f945f7da097245a2f8ed7775ce48421047ee96 · Note
• https://twitter.com/danilofalcao/status/2078947884586717458 · Twitter Post