CVE-2026-27623
Description
A flaw was found in Valkey. A malicious actor with network access to Valkey can cause the system to shut down by sending a specially crafted request. This occurs because the system does not properly reset its networking state after processing an empty request, leading to an assertion failure. This vulnerability results in a Denial of Service (DoS), making the Valkey database unavailable.
Statement
This is an IMPORTANT denial-of-service vulnerability in Valkey versions 9.0.0 through 9.0.2. A remote, unauthenticated attacker with network access to a Valkey instance can send a malformed request, causing the server to terminate due to an assertion failure. This issue arises from improper state handling after processing an empty request.
Mitigation
To mitigate this issue, restrict network access to Valkey deployments. Configure network firewalls or access control lists to ensure that only trusted users and systems can establish connections to the Valkey service. This will limit the exposure to malicious actors and prevent unauthorized denial of service attacks. Reloading network configurations or restarting firewall services may be required for changes to take effect.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker that can trigger an assert statement can still lead to a denial of service if the relevant code can be triggered by an attacker, and if the scope of the assert() extends beyond the attacker's own session.
Frequently Asked Questions
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