CVE intelligence and bounded remediation
CVE-2026-56122 — Winstone Servlet Engine security vulnerability
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.
- Severity
- High
- CVSS
- 8.7 (4.0)
- Published
- 2026-06-25
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-22
Affected products
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Matched remediation archetype
Path traversal, unsafe upload, and file handling
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Check exposure
- Trace untrusted filenames, archive entries, URLs, and path segments into read, write, include, extraction, and upload operations.
- Identify filesystem roots, mount permissions, symbolic-link behavior, archive handling, and whether uploaded content is web-accessible or executable.
- Review canonicalization and containment checks across supported operating systems and storage backends.
Remediate safely
- Generate server-side storage identifiers and resolve paths beneath a fixed root using filesystem-aware containment checks.
- Reject absolute, parent-relative, alternate-separator, device, link, and archive entries that escape the intended root.
- Store uploads outside executable or served paths, validate type and size, and use private atomic temporary files.
Authoritative sources
Complete CVE record and remediation plan
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