Inefficient Regular Expression Complexity Affecting open-webui package, versions <0.11.0-r6


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.61% (47th percentile)

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  • Snyk IDSNYK-WOLFILATEST-OPENWEBUI-18612463
  • published11 Aug 2026
  • disclosed6 Aug 2026

Introduced: 6 Aug 2026

CVE-2026-67422  (opens in a new tab)
CWE-1333  (opens in a new tab)

How to fix?

Upgrade Wolfi open-webui to version 0.11.0-r6 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream open-webui package and not the open-webui package as distributed by Wolfi. See How to fix? for Wolfi relevant fixed versions and status.

pymdown-extensions is a collection of extensions for the Python Markdown library. In versions up to and including 11.0, four inline processors (caret, tilde, betterem, and magiclink) use regular expressions whose content groups can partition a run of delimiter characters in exponentially many ways, causing catastrophic backtracking. As a result, a single untrusted Markdown line under 50 bytes rendered with markdown.markdown() in each extension's default configuration drives the rendering thread into unbounded CPU usage that grows exponentially with input length, enabling an unauthenticated remote attacker who can submit Markdown to cause denial of service. The exposure is concrete for web applications that render user-supplied Markdown (comments, wikis, issue bodies, live preview), including any app using pymdownx.extra which bundles the vulnerable betterem default, as well as hosted docs/CI systems that build untrusted Markdown. The issue has been fixed in version 11.0.1.

CVSS Base Scores

version 3.1