Joplin: Stored XSS in public share viewer via javascript: URL bypass in isAcceptedUrl

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

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.

Source published

21 Sep 2026 21:16:12 UTC

Source modified

29 Sep 2026 13:57:46 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · 4.4 CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N