CVE-2026-23437: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.1% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: net: shaper: protect late read accesses to the hierarchy We look up a netdev during prep of Netlink ops (pre- callbacks) and take a ref to it. Then later in the body of the callback we take its lock or RCU which are the actual protections. This is not proper, a conversion from a ref to a locked netdev must include a liveness check (a check if the netdev hasn't been unregistered already). Fix the read cases (those under RCU). Writes needs a separate change to protect from creating the hierarchy after flush has already run.

Affected products

• Linux Linux Kernel: from 6.13.1, before 6.18.20 (fixed in 6.18.20); from 6.19, before 6.19.10 (fixed in 6.19.10); version 6.13 only; version 7.0 only

Published 2026-04-03. Last modified 2026-07-24.