{"cve":"CVE-2022-31052","nvd":{"published":"2022-06-28T17:15:08.217","modified":"2026-06-17T04:44:41.607","status":"Modified","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":6.5},"cwes":["CWE-674"],"references":["https://github.com/matrix-org/synapse/commit/fa1308061802ac7b7d20e954ba7372c5ac292333","https://github.com/matrix-org/synapse/security/advisories/GHSA-22p3-qrh9-cx32","https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7EARKKJZ2W7WUITFDT4EG4NVATFYJQHF/","https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGSDQ4YAITCUACAB7SXQZDJIU3IQ4CJD/","https://spec.matrix.org/v1.2/client-server-api/#get_matrixmediav3preview_url"],"products":["fedoraproject:fedora","matrix:synapse"],"source":"nvd","synced_at":"2026-10-19T21:32:39.174919249+00:00"},"epss":{"cve":"CVE-2022-31052","score":0.0166,"percentile":0.76664,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-22p3-qrh9-cx32","url":"https://osv.dev/vulnerability/GHSA-22p3-qrh9-cx32","summary":"URL previews of unusual or maliciously-crafted pages can crash Synapse media repositories or Synapse monoliths","modified":"2024-09-30T20:36:03.876361Z","packages":[{"ecosystem":"PyPI","name":"matrix-synapse","purl":"pkg:pypi/matrix-synapse","ranges":["<1.61.1"],"fixed":["1.61.1"]}]},{"id":"PYSEC-2022-224","url":"https://osv.dev/vulnerability/PYSEC-2022-224","summary":"","modified":"2023-11-08T04:09:24.314098Z","packages":[{"ecosystem":"PyPI","name":"matrix-synapse","purl":"pkg:pypi/matrix-synapse","ranges":["<1.61.1"],"fixed":["1.61.1"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}