PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-70480 open-webui CVE debrief

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-08-04T20:16:54.903Z and has not been modified since then. Open WebUI, an extensible and feature-rich self-hosted AI platform, is vulnerable to a security issue. From version 0.6.34 until 0.11.0, Open WebUI renders vega and vega-lite fenced code blocks in chat content by building a Vega view in the viewer browser without a restricted resource loader. This allows any user who can place such a block where another user will see it to make that user's browser issue attacker-chosen outbound GET requests and read responses from same-origin or CORS-permissive targets into the rendered page. The issue is fixed in version 0.11.0. Users of Open WebUI, especially those with limited privileges, should be aware of this vulnerability and take necessary actions to mitigate it. System administrators and security teams responsible for Open WebUI installations should prioritize updating to version 0.11.0 or later.

Vendor
open-webui
Product
Unknown
CVSS
MEDIUM 4.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-08-04
Original CVE updated
2026-09-18
Advisory published
2026-08-04
Advisory updated
2026-09-18

Who should care

Users of Open WebUI, especially those with limited privileges, should be aware of this vulnerability and take necessary actions to mitigate it. System administrators and security teams responsible for Open WebUI installations should prioritize updating to version 0.11.0 or later.

Technical summary

The Open WebUI platform, from version 0.6.34 until 0.11.0, is vulnerable to a security issue where users can make other users' browsers issue attacker-chosen outbound GET requests and read responses from same-origin or CORS-permissive targets. This is due to the rendering of vega and vega-lite fenced code blocks in chat content by building a Vega view in the viewer browser without a restricted resource loader. The issue has been fixed in version 0.11.0.

Defensive priority

Medium priority given the CVSS score of 4.1 and the potential for users with limited privileges to exploit the vulnerability.

Recommended defensive actions

  • Review and update Open WebUI to version 0.11.0 or later to mitigate the vulnerability.
  • Restrict the rendering of vega and vega-lite fenced code blocks in chat content.
  • Implement a restricted resource loader for Vega views in the viewer browser.
  • Monitor for suspicious outbound GET requests from users with limited privileges.
  • Educate users on the potential risks of rendering untrusted content.

Evidence notes

The CVE-2026-70480 issue involves Open WebUI, an extensible, feature-rich, and user-friendly self-hosted AI platform. From version 0.6.34 until 0.11.0, Open WebUI renders vega and vega-lite fenced code blocks in chat content by building a Vega view in the viewer browser without a restricted resource loader. This allows any user who can place such a block where another user will see it to make that user's browser issue attacker-chosen outbound GET requests and read responses from same-origin or CORS-permissive targets into the rendered page. The issue is fixed in version 0.11.0.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-70480 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-70480

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-70480 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-70480

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental 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.