# CVE-2026-123201: buku through 5.1.1 SSRF via bukuserver fetch_data and network_handle API


- **Severity:** Medium 6.3 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 5 Nov 2026
- **Updated:** 9 Nov 2026
- **Also known as:** GHSA-jrwq-3w4r-c27c

## What is CVE-2026-123201?

CVE-2026-123201 is a medium-severity vulnerability in jarun buku, published on 5 Nov 2026. 

### Official description

Buku (bukuserver) through 5.1.1 contains an unauthenticated server-side request forgery vulnerability that allows remote attackers to make the server request internal hosts by supplying a url parameter to /api/fetch_data or /api/network_handle. Attackers can target loopback, private, or cloud metadata IP addresses, which pass the weak is_bad_url() check and follow redirects, to discover internal services and read their page titles, descriptions, and keywords.

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2026-123201?


## How do I fix CVE-2026-123201?

No fix has been published for CVE-2026-123201 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-123201 being exploited?

There is no known exploitation of CVE-2026-123201 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-123201 and fix it if it is affected.

What it is: CVE-2026-123201 is a medium-severity vulnerability in jarun buku, published on 5 Nov 2026. 
Exploitation: There is no known exploitation of CVE-2026-123201 in the wild and no public exploit code.

Affected product: jarun buku. 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-2026-123201/ (Markdown: https://insights.sbomify.com/CVE-2026-123201/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-123201
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-123201
- OSV: https://osv.dev/vulnerability/CVE-2026-123201

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-123201/
Summaries are generated and may contain mistakes; the official description above is the record.