{"cve":"CVE-2024-53863","nvd":{"published":"2024-12-03T17:15:12.633","modified":"2026-06-17T08:09:26.140","status":"Analyzed","description":"Synapse is an open-source Matrix homeserver. In Synapse versions before 1.120.1, enabling the dynamic_thumbnails option or processing a specially crafted request could trigger the decoding and thumbnail generation of uncommon image formats, potentially invoking external tools like Ghostscript for processing. This significantly expands the attack surface in a historically vulnerable area, presenting a risk that far outweighs the benefit, particularly since these formats are rarely used on the open web or within the Matrix ecosystem. Synapse 1.120.1 addresses the issue by restricting thumbnail generation to images in the following widely used formats: PNG, JPEG, GIF, and WebP. This vulnerability is fixed in 1.120.1.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","score":8.2},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","score":9.1},"cwes":["CWE-434"],"references":["https://github.com/element-hq/synapse/security/advisories/GHSA-vp6v-whfm-rv3g"],"products":["matrix:synapse"],"source":"nvd","synced_at":"2026-10-19T21:57:36.180738747+00:00"},"epss":{"cve":"CVE-2024-53863","score":0.00606,"percentile":0.49018,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-vp6v-whfm-rv3g","url":"https://osv.dev/vulnerability/GHSA-vp6v-whfm-rv3g","summary":"Synapse can be forced to thumbnail unexpected file formats, invoking external, potentially untrustworthy decoders","modified":"2026-07-07T17:56:24.772265797Z","packages":[{"ecosystem":"PyPI","name":"matrix-synapse","purl":"pkg:pypi/matrix-synapse","ranges":["<1.120.1"],"fixed":["1.120.1"]}]},{"id":"PYSEC-2026-1615","url":"https://osv.dev/vulnerability/PYSEC-2026-1615","summary":"Synapse can be forced to thumbnail unexpected file formats, invoking external, potentially untrustworthy decoders","modified":"2026-07-07T17:46:57.380988817Z","packages":[{"ecosystem":"PyPI","name":"matrix-synapse","purl":"pkg:pypi/matrix-synapse","ranges":["<1.120.1"],"fixed":["1.120.1"]}]}],"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."]}