CVE-2026-46090 ALSA: aloop: Fix peer runtime UAF during format-change stop
A race condition in the Linux kernel ALSA loopback driver allows a use-after-free, potentially enabling local attackers to execute code or escalate privileges.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-46090?
CVE-2026-46090 is a high-severity use after free vulnerability in Linux kernel, published on 27 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ALSA: aloop: Fix peer runtime UAF during format-change stop
loopback_check_format() may stop the capture side when playback starts with parameters that no longer match a running capture stream. Commit 826af7fa62e3 ("ALSA: aloop: Fix racy access at PCM trigger") moved the peer lookup under cable->lock, but the actual snd_pcm_stop() still runs after dropping that lock.
A concurrent close can clear the capture entry from cable->streams[] and detach or free its runtime while the playback trigger path still holds a stale peer substream pointer.
Keep a per-cable count of in-flight peer stops before dropping cable->lock, and make free_cable() wait for those stops before detaching the runtime. This preserves the existing behavior while making the peer runtime lifetime explicit.
Which versions are affected by CVE-2026-46090?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-46090?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-46090 being exploited?
There is no known exploitation of CVE-2026-46090 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-88571, BELL-CVE-2026-46090, DEBIAN-CVE-2026-46090, GHSA-w9ff-9cjh-6463, ROOT-OS-DEBIAN-11-CVE-2026-46090, ROOT-OS-DEBIAN-12-CVE-2026-46090 and 3 more.