What’s Vulnerable › Vulnerabilities

CVE-2026-42455: LinkWarden: Stored XSS via Client-Side Archive Upload (Unsanitized HTML served from same origin)

• Severity: high (CVSS 8.8 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-09 · updated 2026-07-24
• Weakness: CWE-79

Description

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: through 2.14.0

References

• https://github.com/linkwarden/linkwarden/security/advisories/GHSA-fjvg-mch3-j3vg
• https://github.com/linkwarden/linkwarden/security/advisories/GHSA-fjvg-mch3-j3vg

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