Buffer overflow in Valkey-Io Valkey
CVE-2026-82631
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 2.2 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.006 (45.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 45.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.006 · change: +0.002
Affected products
- Valkey-Io Valkey — versions 9.1.0
Weakness classification (CWE)
References
- vuldb.com/vuln/397129 (technical-description, vdb-entry)
- vuldb.com/vuln/397129/cti (signature, permissions-required)
- vuldb.com/cve/CVE-2026-82631 (third-party-advisory)
- vuldb.com/submit/893793 (third-party-advisory)
- github.com/valkey-io/valkey/issues/4198 (issue-tracking)
- github.com/valkey-io/valkey/pull/4212 (issue-tracking, patch)
- github.com/user-attachments/files/30111628/PoC.zip (exploit)
- github.com/valkey-io/valkey/commit/b2fb0e13f5b4c8c2fb63dcfc2c37a067a0d6d20b (patch)
- github.com/valkey-io/valkey/ (product)
Frequently asked questions
- What is CVE-2026-82631?
- CVE-2026-82631 is a low-severity vulnerability in Valkey-Io Valkey, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 2.2/10. Published 2026-08-31.
- How severe is CVE-2026-82631?
- Low severity. CVSS v3 base score is 2.2 out of 10.