CVE-2018-12423 json
Matrix Synapse Authorization Error
published 2018-06-14 8 y ago modified 2026-07-07 4 mo ago also GHSA-ch5v-fhg8-7gv9 , PYSEC-2026-844 , EUVD-2022-3580
- cvss
- 7.5
- version 3.0, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.8%
- EPSS 1.8% chance of exploitation in 30 days, percentile 78%
- public exploits
- 0
- none known
Summary
In Synapse before 0.31.2, unauthorised users can hijack rooms when there is no m.room.power_levels event in force.
Patch / fix
- pypi matrix-synapse 0.31.2
- matrix synapse 0.31.2
- matrix-synapse Ubuntu Pro 18.04 LTS 0.24.0+dfsg-1ubuntu0.1~esm1
ubuntu advisories UBUNTU-CVE-2018-12423
Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
Exploit prediction
1.81% chance of exploitation in the next 30 days, higher than 78% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.0 | 7.5 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:N/I:P/A:N |
| GitHub | 3.0 | 7.5 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
| OSV | 3.0 | 7.5 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | matrix-synapse | <0.31.2 |
0.31.2 |
References
-
matrix.org
/blog/2018/06/14/security-update-synapse-0-31-2/
vendor-advisory
-
github.com
/matrix-org/matrix-doc/issues/1304
web, third-party-advisory
-
bugs.debian.org
/901549
web, mailing-list, third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2018-12423
advisory
-
github.com
/matrix-org/synapse
package
-
matrix.org
/blog/2018/06/14/security-update-synapse-0-31-2
web
-
pypi.org
/project/matrix-synapse
package
-
github.com
/advisories/GHSA-ch5v-fhg8-7gv9
advisory
Sources
- CVE List CVE-2018-12423
- GitHub Advisory GHSA-ch5v-fhg8-7gv9
- NVD CVE-2018-12423
- OSV PYSEC-2026-844
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