CVE-2026-88001 open-webui CVE debrief

Who should care

Defenders responsible for Open WebUI instances, especially those with AIOHTTP_CLIENT_ALLOW_REDIRECTS enabled, should assess exposure and prioritize remediation. Security teams and administrators of self-hosted AI platforms should verify their deployment contexts and ensure they are running the fixed version.

Why it matters

CVE-2026-88001 is a medium-severity vulnerability in Open WebUI that allows authenticated users to redirect server-side web fetches, potentially leading to unauthorized access or manipulation of sensitive information. Defenders should prioritize verifying exposure, restricting access, and upgrading to the fixed version.

• Potential unauthorized access to sensitive information through cloud metadata services or private networks.
• Possible manipulation of web search, URL ingestion, page-fetch tools, or chat image processing.
• Requires verification of Open WebUI instance exposure and AIOHTTP_CLIENT_ALLOW_REDIRECTS configuration.
• Necessitates upgrading to Open WebUI version 0.11.1 or later for fix.

Technical summary

The vulnerability exists in Open WebUI versions from 0.9.5 to 0.11.0, where server-side web fetches do not reapply WEB_FETCH_FILTER_LIST or private-address controls to HTTP redirect destinations when AIOHTTP_CLIENT_ALLOW_REDIRECTS is enabled. An authenticated user can exploit this to redirect fetches to excluded hosts, loopback, private networks, or cloud metadata services, potentially leading to unauthorized access or manipulation of sensitive information. This issue allows an attacker to route resulting content into web search, URL ingestion, page-fetch tools, or chat image processing, emphasizing the need for defenders to verify exposure, restrict access, and upgrade to the fixed version 0.11.1.

Defensive priority

Defenders should prioritize verifying exposure of Open WebUI instances, especially those with AIOHTTP_CLIENT_ALLOW_REDIRECTS enabled, and ensure they are running version 0.11.1 or later.

Recommended defensive actions

• Verify Open WebUI instance exposure and ensure AIOHTTP_CLIENT_ALLOW_REDIRECTS is disabled if not required.
• Upgrade to Open WebUI version 0.11.1 or later.
• Monitor Open WebUI logs for suspicious redirect activity.
• Restrict access to Open WebUI to trusted users and networks.
• Perform regular security audits to identify potential vulnerabilities.
• Implement additional logging and monitoring to detect unusual activity.
• Review and update incident response plans to address potential exploitation.

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its description, CVSS score, and affected versions. However, there is limited information on potential exploitation or victim impact.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.