valkey-io valkey up to 7.2.11/8.0.6/8.1.5/9.0.1 out-of-bounds

Summaryinfo

A vulnerability, which was classified as problematic, has been found in valkey-io valkey up to 7.2.11/8.0.6/8.1.5/9.0.1. The impacted element is an unknown function. The manipulation leads to out-of-bounds. This vulnerability is listed as CVE-2026-21863. The attack may be initiated remotely. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in valkey-io valkey up to 7.2.11/8.0.6/8.1.5/9.0.1. It has been rated as problematic. This issue affects an unknown functionality. The manipulation with an unknown input leads to a out-of-bounds vulnerability. Using CWE to declare the problem leads to CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. Impacted is availability. The summary by CVE is:

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.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-21863 since 01/05/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 299879 (Linux Distros Unpatched Vulnerability : CVE-2026-21863), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 7.2.12, 8.0.7, 8.1.6 or 9.0.2 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (299879) and CERT Bund (WID-SEC-2026-0546). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

• Debian Linux
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• RESF Rocky Linux

Productinfo

Vendor

• valkey-io

Name

• valkey

Version

• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.2.5
• 7.2.6
• 7.2.7
• 7.2.8
• 7.2.9
• 7.2.10
• 7.2.11
• 8.0.0
• 8.0.1
• 8.0.2
• 8.0.3
• 8.0.4
• 8.0.5
• 8.0.6
• 8.1.0
• 8.1.1
• 8.1.2
• 8.1.3
• 8.1.4
• 8.1.5
• 9.0.0
• 9.0.1

Website

• Product: https://github.com/valkey-io/valkey/

CPE 2.3info

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CPE 2.2info

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