# CVE-2026-57448: Blombooru: administrator image-proxy server-side request forgery


- **Severity:** Medium 6.2 (`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`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 28 Oct 2026
- **Updated:** 28 Oct 2026
- **Also known as:** GHSA-5c5w-x8jp-fjqw

## 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 (Server-Side Request Forgery)

## 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.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-57448 and fix it if it is affected.

What it is: CVE-2026-57448 is a medium-severity vulnerability in mrblomblo blombooru, published on 28 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-57448 in the wild and no public exploit code.

Affected product: mrblomblo blombooru. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-57448/ (Markdown: https://insights.sbomify.com/CVE-2026-57448/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-57448
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-57448
- OSV: https://osv.dev/vulnerability/CVE-2026-57448

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-57448/
Summaries are generated and may contain mistakes; the official description above is the record.