{"cve":"CVE-2026-53724","nvd":{"published":"2026-06-12T19:16:30.220","modified":"2026-10-26T11:10:00.157","status":"Deferred","description":"Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.79 and 9.9.1-alpha.4, the default file upload extension blocklist can be bypassed by appending a trailing dot to a filename whose extension would otherwise be blocked (e.g. poc.svg.). The trailing dot causes the extension parser to extract an empty string, which short-circuits the blocklist check, and the attacker-controlled Content-Type is forwarded to the storage adapter unchanged. Storage adapters that persist and serve the provided Content-Type (such as S3 or GCS) then serve the file with an active type such as image/svg+xml, enabling stored XSS when a victim opens the file URL. The default GridFS adapter is not affected because it sets X-Content-Type-Options: nosniff on responses. This issue has been patched in versions 8.6.79 and 9.9.1-alpha.4.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N","score":2.1},"cvss_v3":null,"cwes":["CWE-79","CWE-434"],"references":["https://github.com/parse-community/parse-server/pull/10489","https://github.com/parse-community/parse-server/pull/10490","https://github.com/parse-community/parse-server/security/advisories/GHSA-7wqv-xjf3-x35v"],"products":[],"source":"nvd","synced_at":"2026-10-26T11:33:08.859761529+00:00"},"epss":{"cve":"CVE-2026-53724","score":0.00281,"percentile":0.20401,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-7wqv-xjf3-x35v","url":"https://osv.dev/vulnerability/GHSA-7wqv-xjf3-x35v","summary":"parse-server: Stored XSS via trailing-dot filename bypassing file upload extension blocklist","modified":"2026-06-19T19:56:23.124647788Z","packages":[{"ecosystem":"npm","name":"parse-server","purl":"pkg:npm/parse-server","ranges":[">=9.0.0 <9.9.1-alpha.4"],"fixed":["9.9.1-alpha.4"]},{"ecosystem":"npm","name":"parse-server","purl":"pkg:npm/parse-server","ranges":["<8.6.79"],"fixed":["8.6.79"]}]}],"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."]}