# CVE-2026-86227: Valkey out-of-bounds read in kvstoreGetHashtable

Source: https://junglewise.ai/threats/cve-2026-86227-valkey-out-of-bounds-read-in-kvstoregethashtable  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-06. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-86227 · Severity: low · CVSS 3.1 · Published 2026-09-06

Valkey is an open-source distributed key-value database used for caching and real-time workloads. A flaw in its cluster mode processing allows an attacker with write access to the data directory to craft a malicious RDB file that triggers an out-of-bounds memory read at startup, potentially causing the server to crash or exposing sensitive data in memory.

## Quick answers

**Is CVE-2026-86227 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-86227 being exploited in the wild.

**How severe is CVE-2026-86227?** Low severity, with a CVSS score of 3.1, published 6 September 2026.

**Which products and versions are affected?** Valkey Valkey up to 9.0.5 and 9.1.1.

**Is there a fix for CVE-2026-86227?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-86227 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-86227?** 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 an out-of-bounds read in the kvstoreGetHashtable function (src/kvstore.c) triggered by manipulation of the didx argument. The flaw requires cluster mode to be enabled, attacker-controlled write access to the data directory (via a crafted RDB file, replication feed, or stored RDB), and occurs at server boot time rather than via remote network authentication. An attacker can cause a denial of service by crashing the server during initialization or potentially leak sensitive data from memory. The issue has been assigned CVE-2026-86227 with a CVSS score of 3.1 (low severity). A patch is available with commit hash 4691888e7fab3df128f0bde5750c9fde2ae552fa.

## Affected products

- Valkey Valkey up to 9.0.5 and 9.1.1

## Timeline

- 2026-09-06: disclosed

## References

- [https://github.com/user-attachments/files/30195539/RDB.zip](https://github.com/user-attachments/files/30195539/RDB.zip)
- [https://github.com/valkey-io/valkey/](https://github.com/valkey-io/valkey/)