CVE-2026-24044Network attack vector

Server impersonation via fixed-seed signing key generation

Published Feb 12, 2026 · Updated Feb 12, 2026

Predictable key generation in Element ESS Community Helm Chart before 25.12.2 allows remote attackers to impersonate Matrix servers. The initialization hook uses matrix-tools to generate Ed25519 signing keys from the same PRNG seed, producing a known public key and reproducible private key. Exposure requires automatic secret initialization without an explicit Synapse signing key and untrusted federation access; past end-to-end encrypted conversations remain confidential.

CVSS severity9.2
Critical
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Predictable key generation in Element ESS Community Helm Chart before 25.12.2 allows remote attackers to impersonate Matrix servers. The initialization hook uses matrix-tools to generate Ed25519 signing keys from the same PRNG seed, producing a known public key and reproducible private key. Exposure requires automatic secret initialization without an explicit Synapse signing key and untrusted federation access; past end-to-end encrypted conversations remain confidential.

The record

CVE
CVE-2026-24044
Published
Feb 12, 2026
Updated
Feb 12, 2026
Vendor
Element HQ
Product
matrix-tools
Classifications
CWE-336, T1552.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 12, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 12, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.5.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Element HQ · matrix-toolsversion=< 0.5.7
Element HQ · ESS Community Helm Chartversion=< 25.12.1

Published CVSS scores

9.2ElementCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-336Same Seed in Pseudo-Random Number Generator (PRNG)
T1552.004Unsecured Credentials: Private Keys

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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