CVE-2026-54017
HIGHOpen WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.6, the terminal-server reverse proxy in `backend/open_webui/routers/terminals.py`…
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Description
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.6, the terminal-server reverse proxy in backend/open_webui/routers/terminals.py does not fully confine the user-controlled path segment before forwarding it to an admin-configured terminal server. An authenticated user who has been granted access to a terminal server can craft path values containing encoded ../ traversal sequences that escape the intended path (or policy) scope on that server, reaching unintended endpoints and files on the terminal-server host. Where the terminal server fans requests out to internal services, this also gives SSRF-style reach into those services. This is a separate code path from the /api/v1/retrieval/process/web SSRF (GHSA-c6xv-rcvw-v685), with its own input. Two distinct vectors are consolidated here: first, raw path forwarding / single-encoded traversal (original report); and second, a bypass of the subsequently-added _sanitize_proxy_path mitigation using double-encoded dots (%252e%252e). The attacker-controlled input is the request path, supplied by the non-admin user, not anything an administrator configures, so this is not an admin-trust / Rule-9 situation. Version 0.9.6 fixes the issue.
Affected Products
open webuiopenwebuiDetection & mitigation playbook
Vendor / applianceDetect
Inventory every openwebui open webui deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Fix
Apply the openwebui open webui security patch or hotfix for CVE-2026-54017 on the affected version, following the vendor advisory for your exact build.
Workarounds
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2026-54017 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.
Tailored to CVE-2026-54017. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-54017 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2026-54017 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.