CVE-2026-24044 ESS Community Helm Chart has a weak server key generation method

What is CVE-2026-24044?

CVE-2026-24044 is a critical vulnerability in element-hq ess-helm, published on 12 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Element Server Suite Community Edition (ESS Community) deploys a Matrix stack using the provided Helm charts and Kubernetes distribution. The ESS Community Helm Chart secrets initialization hook (using matrix-tools container before 0.5.7) is using an insecure Matrix server key generation method, allowing network attackers to potentially recreate the same key pair, allowing them to impersonate the victim server. The secret is generated by the secrets initialization hook, in the ESS Community Helm Chart values, if both initSecrets.enabled is not set to false and synapse.signingKey is not defined. Given a server key in Matrix authenticates both requests originating from and events constructed on a given server, this potentially impacts confidentiality, integrity and availability of rooms which have a vulnerable server present as a member. The confidentiality of past conversations in end-to-end encrypted rooms is not impacted. The key generation issue was fixed in matrix-tools 0.5.7, released as part of ESS Community Helm Chart 25.12.1.

Weakness: CWE-336

Which versions are affected by CVE-2026-24044?

How do I fix CVE-2026-24044?

Upgrade to a fixed version.

Is CVE-2026-24044 being exploited?

There is no known exploitation of CVE-2026-24044 in the wild and no public exploit code.

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-qwcj-h6m8-vp6q, openSUSE-SU-2026:10196-1.