🛡️ CVE-2026-21863 — valkey

🟠 CVSS 8.0 — High ✅ No Known Exploit CWE-125 OSV
8.0
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Malformed Valkey Cluster bus message can lead to Remote DoS

Valkey is a distributed key-value database. Prior to versions 9.0.2, 8.1.6, 8.0.7, and 7.2.12, a malicious actor with access to the Valkey clusterbus port can send an invalid packet that may cause an out bound read, which might result in the system crashing. The Valkey clusterbus packet processing code does not validate that a clusterbus ping extension packet is located within buffer of the clusterbus packet before attempting to read it. Versions 9.0.2, 8.1.6, 8.0.7, and 7.2.12 fix the issue. As an additional mitigation, don't expose the cluster bus connection directly to end users, and protect the connection with its own network ACLs.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability high.

Weakness class

CVE-2026-21863 is classified as CWE-125: Out-of-bounds Read. The code reads past the limits of a buffer, exposing adjacent memory contents or crashing the process.

Affected software

CVE-2026-21863 is recorded against 1 package.

  • valkey

Timeline and source

Published on 26 February 2026 and last revised on 15 July 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

github.com (Web)
nvd.nist.gov (Web)
access.redhat.com (Web)
access.redhat.com (Web)
access.redhat.com (Web)
access.redhat.com (Web)
access.redhat.com (Web)
bugzilla.redhat.com (Web)
security.access.redhat.com (Web)

CVE-2026-21863 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity HIGH
CVSS Score 8.0
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE CWE-125
Public Exploit ✅ No
Source OSV
Published 2026-02-26
Updated 2026-08-12
Modified 2026-07-15
Fix URL N/A

Affected Packages

Software From version Fixed in
valkey — —

Site Security Check

Is valkey part of your stack?

CVE-2026-21863 is rated CVSS 8.0 High. BotEraser scans your installation against known CVE records and tells you whether this vulnerability applies to the versions you actually run.

Scan My Site Free →

No credit card required  ·  Results in minutes

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.