Vulnerability · Published Feb 12, 2026 · Assigned by GitHub_M
CVE-2026-24044ESS Community Helm Chart has a weak server key generation method
Critical 9.2
In plain English
A critical-severity security flaw in ess-helm from element-hq. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.23 | synapse | 1.147.1-r0 | ALPINE-CVE-2026-24044 |
| Alpine:v3.24 | synapse | 1.147.1-r0 | ALPINE-CVE-2026-24044 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| element-hq | ess-helm | < 25.12.1 |
| element-hq | matrix-tools | < 0.5.7 |
Weakness: CWE-336 · Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
References
- https://github.com/element-hq/ess-helm/security/advisories/GHSA-qwcj-h6m8-vp6q x_refsource_CONFIRM
- https://github.com/element-hq/ess-helm/blob/main/docs/maintenance.md#fixing-cve-2026-24044elementsec-2025-1670-manually x_refsource_MISC
- https://github.com/element-hq/ess-helm/releases/tag/25.12.2 x_refsource_MISC