# CVE-2026-82631: Valkey use-after-free in blocked-on-keys subsystem

Source: https://junglewise.ai/threats/cve-2026-82631-valkey-use-after-free-in-blocked-on-keys-subsystem  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-31. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-82631 · Severity: low · CVSS 2.2 · Published 2026-08-31

Valkey is an open-source, in-memory data store used as a cache and message broker in distributed systems. A use-after-free vulnerability in the blocked-on-keys subsystem could allow a remote attacker to crash the service or potentially execute code, impacting availability and data integrity for applications relying on Valkey for caching and real-time operations.

## Quick answers

**Is CVE-2026-82631 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-82631 being exploited in the wild.

**How severe is CVE-2026-82631?** Low severity, with a CVSS score of 2.2, published 31 August 2026.

**Which products and versions are affected?** valkey-io Valkey 9.1.0.

**Is there a fix for CVE-2026-82631?** A patch was published on 2026-08-31: Patch commit b2fb0e13f5b4c8c2fb63dcfc2c37a067a0d6d20b Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-82631 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-82631?** Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is a use-after-free in the handleClientsBlockedOnKey function within src/blocked.c of Valkey's blocked-on-keys subsystem. The flaw occurs through memory manipulation that causes the application to reference freed memory. The attack is network-reachable and requires high complexity to exploit, though a public proof-of-concept has been released. An attacker can trigger a crash or potentially achieve code execution. A patch is available (commit b2fb0e13f5b4c8c2fb63dcfc2c37a067a0d6d20b) and should be applied immediately.

## Affected products

- valkey-io Valkey 9.1.0

## Timeline

- 2026-08-31: disclosed
- 2026-08-31: patched: Patch commit b2fb0e13f5b4c8c2fb63dcfc2c37a067a0d6d20b

## References

- [https://github.com/user-attachments/files/30111628/PoC.zip](https://github.com/user-attachments/files/30111628/PoC.zip)
- [https://github.com/valkey-io/valkey/](https://github.com/valkey-io/valkey/)