# CVE-2026-11437: perfree go-fastdfs-web Installation Endpoint checkServer server-side request forgery

> Remote attackers can exploit the installation endpoint to perform server-side request forgery, potentially accessing internal resources.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 Jun 2026
- **Updated:** 8 Jun 2026
- **Also known as:** GHSA-6g49-gvr8-2cj2

## What is CVE-2026-11437?

CVE-2026-11437 is a medium-severity server-side request forgery vulnerability in perfree go-fastdfs-web, published on 6 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A flaw has been found in perfree go-fastdfs-web up to 1.3.7. Affected is the function checkServer of the file /install/checkServer of the component Installation Endpoint. Executing a manipulation can lead to server-side request forgery. The attack can be executed remotely. The exploit has been published and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

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

## Which versions are affected by CVE-2026-11437?


## How do I fix CVE-2026-11437?

No fix has been published for CVE-2026-11437 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-11437 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-11437 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-11437 and fix it if it is affected.

What it is: CVE-2026-11437 is a medium-severity server-side request forgery vulnerability in perfree go-fastdfs-web, published on 6 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-11437 exists.

Affected product: perfree go-fastdfs-web. 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-2026-11437/ (Markdown: https://insights.sbomify.com/CVE-2026-11437/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-11437
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-11437
- OSV: https://osv.dev/vulnerability/CVE-2026-11437

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-11437/
Summaries are generated and may contain mistakes; the official description above is the record.