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7.5
HIGH CVSS 3.1
CVE-2026-21863
Malformed Valkey Cluster bus message can lead to Remote DoS
Description

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.

INFO

Published Date :

Feb. 23, 2026, 8:28 p.m.

Last Modified :

Feb. 25, 2026, 5:49 p.m.

Remotely Exploit :

Yes !

Source :

[email protected]
Affected Products

The following products are affected by CVE-2026-21863 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Lfprojects valkey
: Total Affected Vendor : 1 | Products : 1
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH [email protected]
Solution
Update Valkey to patched versions and restrict cluster bus access.
  • Update Valkey to version 9.0.2 or later.
  • Update Valkey to version 8.1.6 or later.
  • Update Valkey to version 8.0.7 or later.
  • Update Valkey to version 7.2.12 or later.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-21863.

URL Resource
https://github.com/valkey-io/valkey/security/advisories/GHSA-c677-q3wr-gggq Vendor Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-21863 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-21863 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-21863 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-21863 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Feb. 25, 2026

    Action Type Old Value New Value
    Added CPE Configuration OR *cpe:2.3:a:lfprojects:valkey:*:*:*:*:*:*:*:* versions up to (excluding) 7.2.12 *cpe:2.3:a:lfprojects:valkey:*:*:*:*:*:*:*:* versions from (including) 8.0.0 up to (excluding) 8.0.7 *cpe:2.3:a:lfprojects:valkey:*:*:*:*:*:*:*:* versions from (including) 8.1.0 up to (excluding) 8.1.6 *cpe:2.3:a:lfprojects:valkey:*:*:*:*:*:*:*:* versions from (including) 9.0.0 up to (excluding) 9.0.2
    Added Reference Type GitHub, Inc.: https://github.com/valkey-io/valkey/security/advisories/GHSA-c677-q3wr-gggq Types: Vendor Advisory
  • New CVE Received by [email protected]

    Feb. 23, 2026

    Action Type Old Value New Value
    Added Description 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.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
    Added CWE CWE-125
    Added Reference https://github.com/valkey-io/valkey/security/advisories/GHSA-c677-q3wr-gggq
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 7.5
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact