CVE-2026-54018
HIGHOpen WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.6, the SafePlaywrightURLLoader implements a validate_url function to…
Description
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.6, the SafePlaywrightURLLoader implements a validate_url function to prevent SSRF attacks by checking the IP address of the user-provided URL. However, this validation is performed only on the initial URL. Since Playwright automatically follows HTTP redirects (301/302) by default, an attacker can bypass the validation by providing a safe URL that redirects to a restricted internal network address (e.g., localhost, Docker container network, or Cloud Metadata). This allows the application to access internal services despite ENABLE_RAG_LOCAL_WEB_FETCH being set to False This vulnerability is fixed in 0.9.6.
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-2026-54018 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-2026-54018 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-2026-54018. 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-2026-54018 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2026-54018 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.