CVE-2026-42455: Linkwarden

High severity, CVSS 8.8. EPSS: 0.6% chance of exploitation in the next 30 days.

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.

Affected products

• Linkwarden Linkwarden: up to and including 2.14.0

Published 2026-05-09. Last modified 2026-07-24.