CVE-2026-82631 valkey-io valkey Blocked-on-keys blocked.c handleClientsBlockedOnKey use after free
Remote attackers can exploit a use-after-free flaw in Valkey's blocked-on-keys subsystem, potentially leading to code execution or service disruption.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-82631?
CVE-2026-82631 is a low-severity use after free vulnerability in valkey-io valkey, published on 31 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
A security flaw has been discovered in valkey-io valkey 9.1.0. The affected element is the function handleClientsBlockedOnKey of the file src/blocked.c of the component Blocked-on-keys Subsystem. The manipulation results in use after free. The attack may be performed from remote. A high complexity level is associated with this attack. The exploitability is described as difficult. The exploit has been released to the public and may be used for attacks. The patch is identified as b2fb0e13f5b4c8c2fb63dcfc2c37a067a0d6d20b. Applying a patch is advised to resolve this issue.
Which versions are affected by CVE-2026-82631?
How do I fix CVE-2026-82631?
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-2026-82631 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-82631 exists.
Sources
Also known as AZL-98439, BELL-CVE-2026-82631, DEBIAN-CVE-2026-82631, ECHO-fc1f-17d4-9ed1, GHSA-vxq6-76gw-j6q5, UBUNTU-CVE-2026-82631.