{"cve":"CVE-2023-32683","nvd":{"published":"2023-06-06T19:15:11.963","modified":"2026-06-17T05:59:22.977","status":"Modified","description":"Synapse is a Matrix protocol homeserver written in Python with the Twisted framework. A discovered oEmbed or image URL can bypass the `url_preview_url_blacklist` setting potentially allowing server side request forgery or bypassing network policies. Impact is limited to IP addresses allowed by the `url_preview_ip_range_blacklist` setting (by default this only allows public IPs) and by the limited information returned to the client: 1. For discovered oEmbed URLs, any non-JSON response or a JSON response which includes non-oEmbed information is discarded. 2. For discovered image URLs, any non-image response is discarded. Systems which have URL preview disabled (via the `url_preview_enabled` setting) or have not configured a `url_preview_url_blacklist` are not affected. This issue has been addressed in version 1.85.0. Users are advised to upgrade. User unable to upgrade may also disable URL previews.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N","score":5.4},"cwes":["CWE-918","CWE-863"],"references":["https://github.com/matrix-org/synapse/pull/15601","https://github.com/matrix-org/synapse/security/advisories/GHSA-98px-6486-j7qc","https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/X6DH5A5YEB5LRIPP32OUW25FCGZFCZU2/","https://github.com/matrix-org/synapse/pull/15601","https://github.com/matrix-org/synapse/security/advisories/GHSA-98px-6486-j7qc"],"products":["matrix:synapse"],"source":"nvd","synced_at":"2026-10-19T21:38:24.161619714+00:00"},"epss":{"cve":"CVE-2023-32683","score":0.00605,"percentile":0.48956,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-98px-6486-j7qc","url":"https://osv.dev/vulnerability/GHSA-98px-6486-j7qc","summary":"Synapse has URL deny list bypass via oEmbed and image URLs when generating previews","modified":"2024-09-30T20:48:32.953888Z","packages":[{"ecosystem":"PyPI","name":"matrix-synapse","purl":"pkg:pypi/matrix-synapse","ranges":["<1.85.0"],"fixed":["1.85.0"]}]},{"id":"PYSEC-2023-85","url":"https://osv.dev/vulnerability/PYSEC-2023-85","summary":"","modified":"2023-11-08T04:12:35.562423Z","packages":[{"ecosystem":"PyPI","name":"matrix-synapse","purl":"pkg:pypi/matrix-synapse","ranges":["<1.85.0"],"fixed":["1.85.0"]}]}],"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."]}