CVE-2026-42455 PUBLISHED

LinkWarden: Stored XSS via Client-Side Archive Upload (Unsanitized HTML served from same origin)

Assigner: GitHub_M
Reserved: 27.04.2026 Published: 08.05.2026 Updated: 08.05.2026

Linkwarden is a self-hosted, open-source collaborative bookmark manager to collect, organize and archive webpages. In versions 2.14.0 and prior, the archive upload endpoint (POST /api/v1/archives/[linkId]?format=4) accepts HTML files (text/html) without sanitizing JavaScript content. When the archive is later accessed via GET /api/v1/archives/[linkId]?format=4, the HTML is served with Content-Type: text/html from the Linkwarden origin, without any Content-Security-Policy header. This allows arbitrary JavaScript execution in the context of the authenticated Linkwarden sessio. At time of publication, there are no publicly available patches.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N
CVSS Score: 8.8

Product Status

Vendor linkwarden
Product linkwarden
Versions
  • Version <= 2.14.0 is affected

References

Problem Types

  • CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') CWE