{"cve":"CVE-2021-29453","nvd":{"published":"2021-04-19T19:15:17.717","modified":"2026-06-17T03:47:40.323","status":"Modified","description":"matrix-media-repo is an open-source multi-domain media repository for Matrix. Versions 1.2.6 and earlier of matrix-media-repo do not properly handle malicious images which are crafted to be small in file size, but large in complexity. A malicious user could upload a relatively small image in terms of file size, using particular image formats, which expands to have extremely large dimensions during the process of thumbnailing. The server can be exhausted of memory in the process of trying to load the whole image into memory for thumbnailing, leading to denial of service. Version 1.2.7 has a fix for the vulnerability.","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-770","CWE-400"],"references":["https://github.com/turt2live/matrix-media-repo/releases/tag/v1.2.7","https://github.com/turt2live/matrix-media-repo/security/advisories/GHSA-j889-h476-hh9h","https://hub.docker.com/r/turt2live/matrix-media-repo/tags?page=1&ordering=last_updated","https://github.com/turt2live/matrix-media-repo/releases/tag/v1.2.7","https://github.com/turt2live/matrix-media-repo/security/advisories/GHSA-j889-h476-hh9h"],"products":["matrix-media-repo_project:matrix-media-repo"],"source":"nvd","synced_at":"2026-10-19T21:17:01.373894544+00:00"},"epss":{"cve":"CVE-2021-29453","score":0.01002,"percentile":0.62877,"date":"2026-10-31"},"kev":null,"osv":[],"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."]}