CVE-2026-59221: open-webui terminal proxy path traversal guard bypass via 9x encoded traversal
The fix for GHSA-r2wg-2mcr-66rv is incomplete in v0.9.6 and current main. backend/open_webui/routers/terminals.py documents _sanitize_proxy_path() as decoding until stable, but the implementation stops after 8 unquote() passes. A 9x percent-encoded ../... path parameter remains once-encoded after the loop, passes the posixpath.normpath() and cleaned.startswith('..') checks, and is forwarded to the configured terminal server. The upstream server then receives a decoded traversal path such as /base/../admin/system.
References
- github.com/advisories/GHSA-frvj-c5qp-xj4w
- github.com/open-webui/open-webui/commit/05098d25a58d03738e01c4e85e8852c3b4ad849c
- github.com/open-webui/open-webui/pull/26050
- github.com/open-webui/open-webui/releases/tag/v0.10.0
- github.com/open-webui/open-webui/security/advisories/GHSA-frvj-c5qp-xj4w
- nvd.nist.gov/vuln/detail/CVE-2026-59221
Code Behaviors & Features
Detect and mitigate CVE-2026-59221 with GitLab Dependency Scanning
Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Dependency Scanning using SBOM also detects vulnerabilities from proprietary advisories that this site does not include. Learn more about Dependency Scanning using SBOM →