CVE-2022-39203

highpriority · track · 35EPSS 0.009 · 58 %ileEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.86% (58th) EPSS

CVSS 8.8 · high

Is it mine?

3 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · nvd · osv

EPSS · scored 2026-10-27

matrix-appservice-irc is an open source Node.js IRC bridge for Matrix. 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. The vulnerability has been patched in matrix-appservice-irc 0.35.0. As a workaround operators may 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.

cvss

Technical severity, 0–10. One row per scoring source.

8.8

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.18.8highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 2.8 · impact 5.9

v3.18.8highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · ENISA EU

v3.18.8highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · security-advisories@github.comexploitability 2.8 · impact 5.9

v3.18.8highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · OSV

v3.18.1highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-269USCWE-269US

affected products (3)

Products and version ranges known to be affected.

matrix-org matrix-appservice-irc≤ < 0.35.0enisa_euvdEU
matrix matrix irc bridge< 0.35.0nvdUScpe:2.3:a:matrix:matrix_irc_bridge:*:*:*:*:*:*:*:*
npm matrix-appservice-irc< 0.35.0osvUSpkg:npm/matrix-appservice-irc

advisories (1)

Vendor and ecosystem advisories describing this.

GHSA-xvqg-mv25-rwvwParsing issue in matrix-org/node-irc leading to room takeovers2022-09-15ghsa · osvUS
### 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](https://valentin-lorentz.fr/). ### For more information If you have any questions or comments about this advisory email us at [security@matrix.org](mailto:security@matrix.org).

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd nvd osv NVD CVE.org MITRE

published 2022-09-13modified 2026-06-17

references (8)

External citations — patches, advisories, analysis.

scry

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