CVE-2026-86227 valkey-io valkey kvstore.c kvstoreGetHashtable out-of-bounds
Remote attackers can cause denial of service via out-of-bounds read in Valkey cluster mode if they control the startup RDB file.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-86227?
CVE-2026-86227 is a low-severity memory corruption vulnerability in valkey-io valkey, published on 6 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A weakness has been identified in valkey-io valkey up to 9.0.5/9.1.1. This affects the function kvstoreGetHashtable of the file src/kvstore.c. This manipulation of the argument didx causes out-of-bounds read. It is possible to initiate the attack remotely. The attack is considered to have high complexity. It is indicated that the exploitability is difficult. The exploit has been made available to the public and could be used for attacks. Patch name: 4691888e7fab3df128f0bde5750c9fde2ae552fa. To fix this issue, it is recommended to deploy a patch. Exploitation requires cluster mode plus attacker-controlled dump.rdb at startup (data-dir write access, replication feed, or a stored crafted RDB) - an attacker-position DoS at boot, not network pre-auth. The issue report was closed stating it "is worth fixing for the sake of memory safety… but I don't think it meets our bar for a security disclosure."
Which versions are affected by CVE-2026-86227?
How do I fix CVE-2026-86227?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-86227 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-86227 exists.
Sources
Also known as BELL-CVE-2026-86227, DEBIAN-CVE-2026-86227, GHSA-74wm-q835-hxf9, UBUNTU-CVE-2026-86227.