Is CVE-2026-27623 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-27623 being exploited in the wild.

How severe is CVE-2026-27623?

High severity, with a CVSS score of 7.5, published 23 February 2026.

Which products and versions are affected?

Red Hat Enterprise Linux 10 unaffected; Red Hat Enterprise Linux 9 unaffected.

Is there a fix for CVE-2026-27623?

A patch was published on 2026-02-23: Fixed in version 9.0.3 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-27623 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-27623?

Check whether you run Lfprojects Valkey, Red Hat Enterprise Linux 10 or Red Hat Enterprise Linux 9 at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-27623: Valkey denial of service via reachable assertion in RESP processing

CVE-2026-27623 · Severity: high · CVSS 7.5 · Published 2026-02-23

Valkey is a high-performance database used for storing and retrieving data quickly. A security flaw allows an attacker to crash the database server by sending a specifically formatted network request. This results in a service outage, making the database and any applications relying on it unavailable until it is restarted.

Technologies: Lfprojects Valkey, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9. Vendors: Lfprojects, Red Hat.

Quick answers

Is CVE-2026-27623 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-27623 being exploited in the wild.
How severe is CVE-2026-27623?: High severity, with a CVSS score of 7.5, published 23 February 2026.
Which products and versions are affected?: Red Hat Enterprise Linux 10 unaffected; Red Hat Enterprise Linux 9 unaffected.
Is there a fix for CVE-2026-27623?: A patch was published on 2026-02-23: Fixed in version 9.0.3 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-27623 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-27623?: Check whether you run Lfprojects Valkey, Red Hat Enterprise Linux 10 or Red Hat Enterprise Linux 9 at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A reachable assertion vulnerability (CWE-617) exists in Valkey versions 9.0.0 through 9.0.2. The root cause is a failure to properly reset the networking state after processing an empty RESP (Redis Serialization Protocol) request. An unauthenticated attacker with network access can exploit this by sending a subsequent malformed request that triggers a server-side invariant check, causing the process to abort. This results in a complete denial of service. The issue is resolved in Valkey version 9.0.3. Red Hat reports that their Enterprise Linux 9 and 10 implementations are currently unaffected.

Affected products

Valkey-io Valkey >= 9.0.0, < 9.0.3
Red Hat Red Hat Enterprise Linux 9 unaffected
Red Hat Red Hat Enterprise Linux 10 unaffected

Timeline

2026-02-23: disclosed
2026-02-23: advisory
2026-02-23: patched: Fixed in version 9.0.3

References

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