CVE-2026-74583

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

Description A use-after-free race condition exists in the cls route component of the network scheduler. The route4 classifier uses a 16-slot fastmap cache to store struct route4 filter pointers. A race occurs when a reader identifies a filter and a writer simultaneously unlinks and resets the cache for that filter. If the reader populates the cache via the route4 set fastmap() function after the writer has performed the reset but before the filter is freed, a stale pointer is cached. Subsequent packets then access freed memory through this pointer. This issue was confirmed using KASAN (Kernel Address Sanitizer), a tool used to detect memory errors in the kernel.

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