CVE-2018-12423

Name: CVE-2018-12423
Creator: NVD / NIST
Published: 2018-06-14T21:29:00.253+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

UnknownEPSS 1.82%

Last modified Jun 17, 2026

CVE-2018-12423 is a vulnerability of currently unknown severity. In Synapse before 0.31.2, unauthorised users can hijack rooms when there is no m.room.power_levels event in force.. EPSS estimates a 1.82% chance of exploitation in the next 30 days.

Description

In Synapse before 0.31.2, unauthorised users can hijack rooms when there is no m.room.power_levels event in force.

Metrics

EPSS Probability

1.82%

76.1th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Matrix	Synapse	< 0.31.2

References

https://bugs.debian.org/901549Mailing List, Third Party Advisory
https://github.com/matrix-org/matrix-doc/issues/1304Third Party Advisory
https://matrix.org/blog/2018/06/14/security-update-synapse-0-31-2/Vendor Advisory
https://bugs.debian.org/901549Mailing List, Third Party Advisory
https://github.com/matrix-org/matrix-doc/issues/1304Third Party Advisory
https://matrix.org/blog/2018/06/14/security-update-synapse-0-31-2/Vendor Advisory

Timeline

Published: Jun 14, 2018
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-12423?

In Synapse before 0.31.2, unauthorised users can hijack rooms when there is no m.room.power_levels event in force.

How severe is CVE-2018-12423?

Severity scoring for CVE-2018-12423 is pending analysis. The EPSS model estimates a 1.82% probability of exploitation in the next 30 days.

How do I fix CVE-2018-12423?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2018-12423?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST