# CVE-2026-86539: knowns through 0.33.0 Server-Side Request Forgery via embedding-models endpoint

> Attackers can exploit an SSRF vulnerability in the embedding-models endpoint to enumerate internal hosts and access cloud metadata via unvalidated outbound requests.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 7 Sep 2026
- **Updated:** 24 Sep 2026
- **Also known as:** GHSA-fc26-7cjr-27x6, GHSA-qx9v-m9gg-p5jg

## What is CVE-2026-86539?

CVE-2026-86539 is a medium-severity server-side request forgery vulnerability in knowns-dev knowns, published on 7 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

knowns through 0.33.0 contains a server-side request forgery vulnerability in the POST /api/embedding-models/test endpoint that issues outbound requests to caller-supplied destinations without validation. Attackers can enumerate internal hosts and cloud metadata endpoints by observing transport error messages that reveal network reachability information.

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

## Which versions are affected by CVE-2026-86539?


## How do I fix CVE-2026-86539?

No fix has been published for CVE-2026-86539 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-86539 being exploited?

There is no known exploitation of CVE-2026-86539 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-86539 and fix it if it is affected.

What it is: CVE-2026-86539 is a medium-severity server-side request forgery vulnerability in knowns-dev knowns, published on 7 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-86539 in the wild and no public exploit code.

Affected product: knowns-dev knowns. 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-2026-86539/ (Markdown: https://insights.sbomify.com/CVE-2026-86539/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-86539
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-86539
- OSV: https://osv.dev/vulnerability/CVE-2026-86539

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-86539/
Summaries are generated and may contain mistakes; the official description above is the record.