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CVE-2026-49449GHSA-9M2R-PV96-JXR3

Joplin: KaTeX `trust:true` enables URL-allowlist bypass leading to NTLMv2 credential theft via UNC path on Windows

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 3.7.2
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: poc
  • Automatable: no
  • Technical impact: partial

Summary

Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. From 1.4.0 until 3.7.2, packages/renderer/MdToHtml/rules/katex.ts enables KaTeX's trust option for note content, allowing a note author to place a \href URL into rendered output without passing Joplin's normal URL allowlist. On Windows, clicking a link whose target is an attacker-controlled UNC path causes pathExists() to initiate SMB authentication and disclose the current user's NTLMv2 challenge-response without a warning. The unfiltered URL can also invoke other registered URL handlers, but the credential disclosure through KaTeX \href is the distinguishing demonstrated impact. This issue is fixed in version 3.7.2.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: poc · Automatable: no · Technical impact: partial

  3. Record last updated

Affected versions

  • laurent22 joplin

    From 1.4.0 · fixed in 3.7.2

References 3

GitHub · laurent22/joplin