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PatchSiren cyber security CVE debrief

CVE-2026-45299 open-webui CVE debrief

Open WebUI versions prior to 0.8.0 contain a stored cross-site scripting (XSS) vulnerability in the user profile update functionality. The `profile_image_url` field accepted arbitrary `data:` URI values without MIME-type validation, allowing attackers with authenticated access to inject malicious JavaScript payloads that execute in victims' browsers. The vulnerability requires low attack complexity and user interaction, with potential for session hijacking or unauthorized actions within the application context. The issue was remediated in version 0.8.0 through proper input validation.

Vendor
open-webui
Product
Unknown
CVSS
MEDIUM 5.4
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-15
Original CVE updated
2026-05-18
Advisory published
2026-05-15
Advisory updated
2026-05-18

Who should care

Organizations running self-hosted Open WebUI instances, particularly those with multi-user deployments where user-generated content is displayed to other users. Security teams responsible for AI/ML platform hardening and developers maintaining Open WebUI forks or custom deployments.

Technical summary

The vulnerability exists in the user profile update form where the `profile_image_url` parameter accepted arbitrary `data:` URI schemes without validating the declared MIME type against an allowlist. An authenticated attacker could supply a crafted data URI containing JavaScript (e.g., `data:text/html,<script>...`) that would be stored and later rendered in contexts where the profile image is displayed, executing in the security context of other users' sessions. The CVSS v3.1 score of 5.4 (Medium) reflects the required user interaction and limited scope of impact. The fix in version 0.8.0 implements proper MIME-type validation restricting profile images to known safe image formats.

Defensive priority

medium

Recommended defensive actions

  • Upgrade Open WebUI to version 0.8.0 or later to eliminate the vulnerability
  • Review user profile update logs for suspicious data: URI patterns in profile_image_url fields prior to upgrade
  • Implement Content Security Policy (CSP) headers as defense-in-depth against XSS vectors
  • Validate that profile image inputs conform to expected image MIME types (image/jpeg, image/png, image/webp, image/gif)
  • Audit existing user profiles for injected payloads if running versions prior to 0.8.0

Evidence notes

NVD analyzed status confirms technical details. GitHub Security Advisory GHSA-6gh2-q7cp-9qf6 provides vendor mitigation guidance. CVSS 3.1 vector AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N reflects network attack vector, low complexity, required privileges and user interaction, with changed scope and low confidentiality/integrity impact.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-45299 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-45299

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

  • CVE-2026-45299 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-45299

    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.