CVE-2026-57448 Blombooru: administrator image-proxy server-side request forgery
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-57448?
CVE-2026-57448 is a medium-severity vulnerability in mrblomblo blombooru, published on 28 Oct 2026.
Official description
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.
Weakness: CWE-918
Which versions are affected by CVE-2026-57448?
How do I fix CVE-2026-57448?
No fix has been published for CVE-2026-57448 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-57448 being exploited?
There is no known exploitation of CVE-2026-57448 in the wild and no public exploit code.
Sources
Also known as GHSA-5c5w-x8jp-fjqw.