CVE-2022-31052
URL previews can crash Synapse media repositories or Synapse monoliths
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
Synapse is an open source home server implementation for the Matrix chat network. In versions prior to 1.61.1 URL previews of some web pages can exhaust the available stack space for the Synapse process due to unbounded recursion. This is sometimes recoverable and leads to an error for the request causing the problem, but in other cases the Synapse process may crash altogether. It is possible to exploit this maliciously, either by malicious users on the homeserver, or by remote users sending URLs that a local user's client may automatically request a URL preview for. Remote users are not able to exploit this directly, because the URL preview endpoint is authenticated. Deployments with `url_preview_enabled: false` set in configuration are not affected. Deployments with `url_preview_enabled: true` set in configuration **are** affected. Deployments with no configuration value set for `url_preview_enabled` are not affected, because the default is `false`. Administrators of homeservers with URL previews enabled are advised to upgrade to v1.61.1 or higher. Users unable to upgrade should set `url_preview_enabled` to false.
Timeline
ID reserved
By GitHub_M
- 41 days later
· 41 days later
Published
- 3 years later
· 3 years 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 | Medium6.5 | CVSS:3.1/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)
- 1.7% · top 23% 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 < 1.61.1
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- PyPImatrix-synapseGHSA-22p3-qrh9-cx32 (opens in a new tab)
References (5)
- https://github.com/matrix-org/synapse/security/advisories/GHSA-22p3-qrh9-cx32 (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://github.com/matrix-org/synapse/commit/fa1308061802ac7b7d20e954ba7372c5ac292333 (opens in a new tab)x_refsource_MISCx_transferred
- https://spec.matrix.org/v1.2/client-server-api/#get_matrixmediav3preview_url (opens in a new tab)x_refsource_MISCx_transferred
- FEDORA-2022-45bf6d4b88 (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- FEDORA-2022-1a2312e4d6 (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_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-22p3-qrh9-cx32 (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-2022-31052)Record last updated .