PT-2026-51892 · Linux · Linux

Published 2026-06-24 · Updated 2026-06-24 · CVE-2026-52998

Mitre

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nfnetlink osf: fix potential NULL dereference in ttl check

The nf osf ttl() function accessed skb->dev to perform a local interface address lookup without verifying that the device pointer was valid.

Additionally, the implementation utilized an in dev for each ifa rcu loop to match the packet source address against local interface addresses. It assumed that packets from the same subnet should not see a decrement on the initial TTL. A packet might appear it is from the same subnet but it actually isn't especially in modern environments with containers and virtual switching.

Remove the device dereference and interface loop. Replace the logic with a switch statement that evaluates the TTL according to the ttl check.

Related Identifiers

CVE-2026-52998

Affected Products

Linux

References · 9

• https://nvd.nist.gov/vuln/detail/CVE-2026-52998 · Security Note
• https://git.kernel.org/stable/c/95be653a76793856ff8b2d8bd82c2943c23f5ca8 · Note
• https://git.kernel.org/stable/c/79b90a96688e521771fa6ed3dc7864b76b8df293 · Note
• https://git.kernel.org/stable/c/83fc5dd63455a779ea2dd0f7ffee3c920919d80b · Note
• https://git.kernel.org/stable/c/f4de0777e4554a7de19c920accde6319dd530782 · Note
• https://git.kernel.org/stable/c/711987ba281fd806322a7cd244e98e2a81903114 · Note
• https://git.kernel.org/stable/c/edc806f9122961f0d3819f7c69c14cccde31f277 · Note
• https://git.kernel.org/stable/c/5d05de2f0928d81309a815ecc76d1a3ad72cbc16 · Note
• https://git.kernel.org/stable/c/c996a90f3071cf43683e5423da31aadbe002b8b4 · Note