CVE-2026-46650: Joplin: Stored XSS in public share viewer via javascript: URL bypass in isAcceptedUrl

Vulnerability summary

CVE-2026-46650 is a medium (CVSS 4.4) Cross-site Scripting vulnerability in laurent22 joplin. EPSS estimates a 0.28% chance of exploitation in the next 30 days, higher than 19.5% of scored vulnerabilities.

Timeline

1. 21-09-2026
   PublishedVulnerability first disclosed.
2. 29-09-2026
   Last modifiedVulnerability information updated.

Description

Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Prior to 3.7.2, isAcceptedUrl() in packages/renderer/htmlUtils.ts uses an unanchored regular expression for internal resource URLs, allowing a javascript: URL containing a matching 32-character path fragment to pass validation and be emitted into an HTML note's link. A low-privileged Joplin Server user can publish the crafted HTML note as a public share. In the current build, ordinary left-click is blocked; demonstrated execution requires middle-click or Open in new tab in an older or non-hardened browser because current Chrome and Firefox block javascript: new-tab navigation. When execution succeeds, the script runs in the Joplin Server origin, can read page-visible content, and can make authenticated same-origin requests when the victim is signed in. This issue is fixed in version 3.7.2.

• CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.