Out-of-bounds read in Valkey - CVE-2026-21863
Published: April 27, 2026
Vulnerability identifier: #VU128025
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-21863
CWE-ID: CWE-125
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vendor: Valkey
Affected software:
Valkey
Valkey
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to out-of-bounds read in the clusterbus packet processing code when processing a malformed clusterbus ping extension packet. A remote attacker can send a specially crafted clusterbus packet to cause a denial of service.
Exploitation requires access to the Valkey clusterbus port.
How to mitigate CVE-2026-21863
Install security update from vendor's website.