CVE-2026-57448

Blombooru: administrator image-proxy server-side request forgery

Published Oct 28, 2026 CVSS 4.0 · 6.2 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

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History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Mrblomblo
Mrblomblo blombooru
Vendors & Products Mrblomblo
Mrblomblo blombooru
Type Values Removed Values Added
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.
Title Blombooru: administrator image-proxy server-side request forgery
Weaknesses CWE-918
References
Metrics cvssV4_0

{'score': 6.2, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:N/VA:N/SC:H/SI:L/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Nov 3, 2026, 12:06 AM
Reserved
Jun 24, 2026, 1:21 PM
Status
Deferred
Published
Oct 28, 2026, 10:17 PM
Modified
Nov 3, 2026, 1:16 AM