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CVE-2026-59220

CVE-2026-59220 · Open WebUI: ReDoS in skill-mention regexes causes whole-instance DoS on default config

This page contains facts from public vulnerability sources. Check the original advisory before updating.

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.2 before 0.10.0, the SKILL_MENTION_RE and strip_re regular expressions in backend/open_webui/utils/middleware.py parsed <$skillId|label> skill mentions with overlapping quantifiers, allowing an authenticated chat message containing <$ without a closing > to trigger quadratic backtracking and block the asyncio event loop. This issue is fixed in version 0.10.0.

CVSS 6.5 · Medium · EPSS 0.6% · Fix available

Published
Updated

Stack: python

Affected products and versions

  • open-webui

    Versions
    • >= 0.9.2, < 0.10.0: Affected

    No fix published

  • open-webui PyPI

    Versions
    • 0.9.2
    • 0.9.3
    • 0.9.4
    • 0.9.5
    • 0.9.6
    Affected ranges
    • ECOSYSTEM: ≥ 0.9.2, < 0.10.0

    Update to 0.10.0

Original sources

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