# CVE-2026-63639: Valkey use-after-free in RESTORE command RDB stream deserialization

Source: https://junglewise.ai/threats/cve-2026-63639-valkey-use-after-free-in-restore-command-rdb-stream  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-18. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-63639 · Severity: high · CVSS 8.8 · Published 2026-08-18

Valkey is a distributed key-value database used to cache and store data in production systems. A flaw in how Valkey processes the RESTORE command can cause the application to crash or potentially execute arbitrary code when a specially crafted database snapshot is loaded. An attacker with network access to a Valkey instance could trigger this vulnerability to disrupt service or gain control of the database server.

## Quick answers

**Is CVE-2026-63639 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-63639 being exploited in the wild.

**How severe is CVE-2026-63639?** High severity, with a CVSS score of 8.8, published 18 August 2026.

**Which products and versions are affected?** Valkey Valkey prior to 7.2.14, 8.0.10, 8.1.9, 9.0.5, and 9.1.1.

**Is there a fix for CVE-2026-63639?** A patch was published on 2026-08-18: Fixed in versions 7.2.14, 8.0.10, 8.1.9, 9.0.5, and 9.1.1 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-63639 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-63639?** 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 Valkey's RDB stream consumer-group deserialization logic. When the RESTORE command processes a malformed RDB payload, it can create a situation where a single Pending Entry List (NACK) is assigned to multiple consumers without validation. When one consumer is later deleted, the shared NACK is freed but another consumer still holds a reference to it, causing a use-after-free condition. This flaw requires sending a specially crafted RDB stream payload to the RESTORE command and can allow remote code execution. The vulnerability is fixed in versions 7.2.14, 8.0.10, 8.1.9, 9.0.5, and 9.1.1 by adding validation to reject corrupt RDB payloads where a NACK is assigned to multiple consumers.

## Affected products

- Valkey Valkey prior to 7.2.14, 8.0.10, 8.1.9, 9.0.5, and 9.1.1

## Timeline

- 2026-08-18: disclosed
- 2026-08-18: patched: Fixed in versions 7.2.14, 8.0.10, 8.1.9, 9.0.5, and 9.1.1

## References

- [https://github.com/valkey-io/valkey/commit/06bc7768fe609f2054e69ccedefe7628f5675da9](https://github.com/valkey-io/valkey/commit/06bc7768fe609f2054e69ccedefe7628f5675da9)
- [https://github.com/valkey-io/valkey/commit/509cb3c74e8cbc9c0498ebe8b6c93dcd605e7271](https://github.com/valkey-io/valkey/commit/509cb3c74e8cbc9c0498ebe8b6c93dcd605e7271)