Medium

Matrix IRC Bridge truncated content of messages can be leaked

  • Disclosed: 11.04.2024
  • Updated: 11.10.2026 10:22

Impact

The matrix-appservice-irc before version 2.0.0 can be exploited to leak the truncated body of a message if a malicious user sends a Matrix reply to an event ID they don't have access to. As a precondition to the attack, the malicious user needs to know the event ID of the message they want to leak, as well as to be joined to both the Matrix room and the IRC channel it is bridged to.

The message reply containing the leaked message content is visible to IRC channel members when this happens.

Patches

matrix-appservice-irc 2.0.0 checks whether the user has permission to view an event before constructing a reply. Administrators should upgrade to this version.

Workarounds

It's possible to limit the amount of information leaked by setting a reply template that doesn't contain the original message. See these lines in the configuration file.

References

https://github.com/matrix-org/matrix-appservice-irc/pull/1799

For more information

If you have any questions or comments about this advisory, please email us at security at matrix.org.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
npm package matrix-appservice-irc < 2.0.0 2.0.0

References

CVSS score 4.3/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Weakness (CWE)
CWE-280
Platform
npm
Package
matrix-appservice-irc
Disclosed
11.04.2024
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-wm4w-7h2q-3pf7 - CC BY 4.0

Vulnerability history: matrix-appservice-irc

All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (9) in the archive
Total entries
9
First → latest
05.2022 02.2025
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • High 2
  • Medium 5
  • Low 2

Disclosures per year

  1. 2022: 4
  2. 2023: 2
  3. 2024: 2
  4. 2025: 1
  5. 2026: 0
Severity:
  1. Matrix IRC Bridge truncated content of messages can be leaked this entry
    Medium · 4.3 CVE-2024-32000 < 2.0.0 2.0.0
  2. High · 8.8 CVE-2022-39203 < 0.35.0 0.35.0

Know which vulnerabilities affect your application

With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.

Connect your application
DockRay newsletter

Application security in your inbox

Important vulnerabilities, actionable guidance and practical advice for your applications. Choose your technologies and follow what matters to your project.

  • A daily digest of new vulnerabilities, critical ones included.
  • Notifications about important updates.
  • Practical advice on application security and monitoring.

Leave empty to receive updates for every technology.

Free to subscribe. Unsubscribe with one click in any email.