CVE Catalog

CVE-2026-57448

MediumCVSS 6.2
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.34%

28th percentile - higher than 28% of all known CVEs

Summary

Prior to 1.40.0, Blombooru's administrator-only GET /proxy-image endpoint, exposed as /api/booru-import/proxy-image, accepts a url query parameter and fetches it server-side without meaningful destination validation. proxy_image() only checks whether the value starts with http, then uses get_client_for_url or requests.get and streams the response; private, loopback, and link-local addresses are not blocked, and automatically followed redirects can move a request from a trusted domain to an internal address.

Risk Assessment

An authenticated administrator can enumerate internal services and access cloud instance metadata, potentially disclosing IAM credentials and crossing the application's intended cloud or network trust boundary. Administrator authentication is required, so this is not an anonymous proxy.

Recommendation

Upgrade Blombooru to version 1.40.0 or later. Restrict the proxy-image endpoint to trusted domains, block private, loopback, and link-local addresses, and control redirects.

Related vulnerabilities

Original NVD description (English source)

Blombooru is a self-hosted personal booru for organizing and tagging private image collections. Prior to 1.40.0, the administrator-only `GET /proxy-image` endpoint, exposed as `/api/booru-import/proxy-image`, accepts a `url` query parameter and fetches it server-side without meaningful destination validation. `proxy_image()` in `backend/app/routes/booru_import.py` only checks whether the value starts with http, then uses `get_client_for_url` or `requests.get` and streams the response. Private, loopback and link-local addresses are not blocked, and automatically followed redirects can move a request from a trusted domain to an internal address. An authenticated administrator can enumerate internal services and access cloud instance metadata, potentially disclosing IAM credentials and crossing the application's intended cloud or network trust boundary. The reporter also observed a hanging recursive self-request. Administrator authentication remains a prerequisite; this is not an anonymous proxy. This issue is fixed in version 1.40.0.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS