CVE-2022-39374
Synapse Denial of service due to incorrect application of event authorization rules during state resolution
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. If Synapse and a malicious homeserver are both joined to the same room, the malicious homeserver can trick Synapse into accepting previously rejected events into its view of the current state of that room. This can be exploited in a way that causes all further messages and state changes sent in that room from the vulnerable homeserver to be rejected. This issue has been patched in version 1.68.0
Timeline
ID reserved
By GitHub_M
- 9 months later
· 9 months later
Published
- 21 months later
· 21 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.0 | Medium6.5 | CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | Medium6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.94% · top 39% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.5.
Weakness
Affected products
- affected >= 1.62.0, < 1.68.0
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- PyPImatrix-synapseGHSA-p9qp-c452-f9r7 (opens in a new tab)
References (3)
- https://github.com/matrix-org/synapse/security/advisories/GHSA-p9qp-c452-f9r7 (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://github.com/matrix-org/synapse/pull/13723 (opens in a new tab)x_refsource_MISCx_transferred
- https://lists.fedoraproject.org/archives/list/[email protected]/message/UJIJRP5ZH6B3KGFLHCAKR2IX2Y4Z25QD/ (opens in a new tab)x_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-p9qp-c452-f9r7 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2022-39374)Record last updated .