CVE-2026-55105

LOWCVSS 7.7 · HIGH

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Track advisory updates for patch or workaround availability

Recommended action window: Monitor and triage in normal cycle

NVD description

Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Prior to 3.6.15 and 3.7.2, packages/renderer/MdToHtml/rules/fountain.ts passes HTML generated by the vendored fountain.js renderer into note output without sanitizing it. A malicious Fountain code block can therefore execute script when Fountain rendering is enabled in desktop or mobile clients, or when a note is published through Joplin Server where Fountain rendering is enabled by default. The script can read content subsequently loaded in the reused note viewer or, when published notes are served from the same domain as server content, access data available to an authenticated browser in the server origin. This issue is fixed in versions 3.6.15 and 3.7.2.

0.0/ 10 priority

Sources & remediation

Weakness type (CWE)
CWE-79

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

NONE

Momentum

NONE

Threat summary

  • 1 mentions across 1 observed day

What's happening

  • 1 total mentions across 1 day

Deep dive

Activity timeline1 mentions / 1d
00111Mentions · 2026-10-12: 110-12
Full discourse1 post
  • DFIR Lab@DFIR_Lab

    🚨 HIGH Severity: CVE-2026-55105 (CVSS 7.7) Joplin note-taking app vulnerable to XSS via unsanitized Fountain code blocks. Malicious scripts can execute & access note content. Fixed in v3.6.15 & v3.7.2 - UPDATE NOW #CVE #Vulnerability #PatchNow https://t.co/Q7fDvrafdJ

    0000039
    147 followersView on X

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