CVE-2024-39691Network attack vector

Message disclosure via forged homeserver timestamps

Published Jul 5, 2024 · Updated Aug 2, 2024

Information disclosure in Matrix.org matrix-appservice-irc before 2.0.1 allows remote attackers to read truncated room messages. MatrixHandler._onMemberEvent stores the homeserver-supplied origin_server_ts as a member's join time, and reply visibility trusts that value. Exploitation requires a malicious Matrix homeserver joined to the bridged room; a forged timestamp exposes only truncated original-message content.

CVSS severity4.3
Medium
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Matrix.org matrix-appservice-irc before 2.0.1 allows remote attackers to read truncated room messages. MatrixHandler._onMemberEvent stores the homeserver-supplied origin_server_ts as a member's join time, and reply visibility trusts that value. Exploitation requires a malicious Matrix homeserver joined to the bridged room; a forged timestamp exposes only truncated original-message content.

The record

CVE
CVE-2024-39691
Published
Jul 5, 2024
Updated
Aug 2, 2024
Vendor
Matrix.org
Product
matrix-appservice-irc
Classifications
CWE-755, CWE-280, T1213.005
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 5, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 2024Record 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=< 2.0.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Matrix.org · matrix-appservice-ircversion=< 2.0.1

Published CVSS scores

4.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A: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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-755Improper Handling of Exceptional Conditions
CWE-280Improper Handling of Insufficient Permissions or Privileges
T1213.005Data from Information Repositories: Messaging Applications

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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