CVE-2023-42453Improper validation of receipts allows forged read receipts in matrix synapse
- 3.1LowCVSS base score
- 0.78%Exploitation in 30 daysEPSS · top 44% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. Users were able to forge read receipts for any event (if they knew the room ID and event ID). Note that the users were not able to view the events, but simply mark it as read. This could be confusing as clients will show the event as read by the user, even if they are not in the room. This issue has been patched in version 1.93.0. Users are advised to upgrade. There are no known workarounds for this issue.
Timeline
ID reserved
By GitHub_M
- 18 days later
· 18 days 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) | 3.1 | Low3.1 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N |
| NVDNVD · Modified | 3.1 | Medium4.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N |
- EPSS (exploitation in 30 days)
- 0.78% · top 44% of all CVEs (14 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: Low 3.1.
Affected products
- affected >= 0.34.0, < 1.93.0
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- PyPImatrix-synapseGHSA-7565-cq32-vx2x (opens in a new tab)
References
References6
- https://github.com/matrix-org/synapse/security/advisories/GHSA-7565-cq32-vx2x (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://github.com/matrix-org/synapse/pull/16327 (opens in a new tab)x_refsource_MISCx_transferred
- https://lists.fedoraproject.org/archives/list/[email protected]/message/65QPC55I4D27HIZP7H2NQ34EOXHPP4AO/ (opens in a new tab)x_transferred
- https://lists.fedoraproject.org/archives/list/[email protected]/message/2AFB2Y3S2VCPCN5P2XCZTG24MBMZ7DM4/ (opens in a new tab)x_transferred
- https://lists.fedoraproject.org/archives/list/[email protected]/message/N6P4QULVUE254WI7XF2LWWOGHCYVFXFY/ (opens in a new tab)x_transferred
- https://security.gentoo.org/glsa/202401-12 (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)
- EUVD EUVD-2023-0133 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-7565-cq32-vx2x (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2023-42453)Record last updated .