{"id":"CVE-2026-53607","aliases":["GHSA-34pj-2622-jvxq"],"url":"https://o3.security/vulnerability/CVE-2026-53607","summary":"@apostrophecms/file pretty-URL Vulnerable to Unauthenticated SSRF via Host header","details":"ApostropheCMS is an open-source Node.js content management system. In versions up to and including 4.30.0, when `prettyUrls: true` is enabled on `@apostrophecms/file` (a documented SEO feature for serving uploaded files at clean URLs), the public pretty-URL handler builds the upstream URL using the raw `Host` HTTP request header. That URL is then `fetch`'ed and the response body + headers are streamed straight back to the requester. Because `Host` is fully attacker-controlled, an unauthenticated remote attacker can pivot the apostrophe process to issue outbound HTTP requests against any host it can reach on the private network. The path component is constrained to `/uploads/attachments/<cuid>-<slug>.<ext>` (built from a local-DB lookup), which keeps the impact narrow: cross-instance data exfiltration is neutralized by cuid uniqueness, but blind-SSRF residuals remain (network-topology mapping via response-code / timing differences and verbose proxy/WAF 404 body disclosure). As of time of publication, no known patched versions exist.","published":"2026-06-12T20:54:30.866Z","modified":"2026-08-12T03:51:46.458703616Z","cvss":{"score":3.7,"severity":"LOW","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"apostrophe","fixedVersion":"4.31.0"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53607.json"},{"type":"ADVISORY","url":"https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-34pj-2622-jvxq"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53607"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:46.458703616Z"}}