Parsing issue in matrix-org/node-irc leading to room takeovers

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.8 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2022-39203: 0.86% estimated exploitation activity in the next 30 days; percentile 58.66 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact Attackers can specify a specific string of characters, which would confuse the bridge into combining an attacker-owned channel and an existing channel, allowing them to grant themselves permissions in the channel. Patched The vulnerability has been patched in matrix-appservice-irc 0.35.0. Workarounds Disable dynamic channel joining via dynamicChannels.enabled to prevent users from joining new channels, which prevents any new channels being bridged outside of what is already bridged, and what is specified in the config. References - https://matrix.org/blog/2022/09/13/security-release-of-matrix-appservice-irc-0-35-0-high-severity Credits Discovered and reported by Val Lorentz. For more information If you have any questions or comments about this advisory email us at security@matrix.org.

Published by the source

15 Sep 2022, 03:26 UTC

Last modified by the source

8 Nov 2023, 04:10 UTC

Source last checked

26 Oct 2026, 12:16 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-xvqg-mv25-rwvw

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-xvqg-mv25-rwvw

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# Patch Next advisory brief: CVE-2022-39203

Advisory: Parsing issue in matrix-org/node-irc leading to room takeovers
IDs: CVE-2022-39203, GHSA-xvqg-mv25-rwvw
Record: https://patchnext.com/advisories/cve-2022-39203 (revision 2, source checked 26 Oct 2026, 12:16 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: matrix-appservice-irc 0.35.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm matrix-appservice-irc: affected < 0.35.0; fixed in 0.35.0

## Suggested inspection (read-only)
- `npm ls matrix-appservice-irc --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on matrix-appservice-irc.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-xvqg-mv25-rwvw (OSV record GHSA-xvqg-mv25-rwvw lists affected ranges: npm matrix-appservice-irc >=0 <0.35.0 (fixed))
- Verified: https://github.com/advisories/GHSA-xvqg-mv25-rwvw (GitHub-reviewed advisory GHSA-xvqg-mv25-rwvw lists affected ranges: npm matrix-appservice-irc >=0 <0.35.0)

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