CVE-2026-21863 — Malformed Valkey Cluster bus message can lead to Remote DoS

Description (CNA)

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.

Affected (CNA)

Vendor / product	Versions
valkey-io / valkey	affected < 7.2.12; affected >= 8.0.0, < 8.0.7; affected >= 8.1.0, < 8.1.6; affected >= 9.0.0, < 9.0.2

CWE

CWE-125

References

https://github.com/valkey-io/valkey/security/advisories/GHSA-c677-q3wr-gggq

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.

redhat-SADP

A flaw was found in Valkey, a distributed key-value database. A malicious actor with access to the Valkey clusterbus port can exploit an input validation vulnerability by sending a specially crafted invalid clusterbus packet. This lack of validation for clusterbus ping extension packets can lead to an out-of-bounds read. Consequently, this may cause the system to crash, resulting in a Denial of Service (DoS).