PT-2026-39223 · Unknown · Linkwarden

Daniel31X13 · Published 2026-05-08 · Updated 2026-05-12 · CVE-2026-42455

Positive Technologies (AI Summary)

CVSS v4.0

8.8

High

Base vector

AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Name of the Vulnerable Software and Affected Versions Linkwarden versions prior to 2.14.0

Description The archive upload endpoint "POST /api/v1/archives/[linkId]?format=4" accepts HTML files without sanitizing JavaScript content. When the archive is accessed via "GET /api/v1/archives/[linkId]?format=4", the HTML is served with Content-Type: text/html from the origin without a Content-Security-Policy header. This enables stored Cross-Site Scripting (XSS), which is a flaw where a malicious script is permanently stored on the target server, allowing arbitrary JavaScript execution within the context of the authenticated session.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

XSS

Weakness Enumeration

CWE-79

Related Identifiers

CVE-2026-42455

Affected Products

Linkwarden

References · 8

• 🔥 https://github.com/linkwarden/linkwarden/security/advisories/GHSA-fjvg-mch3-j3vg · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2026-42455 · Security Note
• https://t.me/cveNotify/162833 · Telegram Post
• https://twitter.com/CVEarity/status/2053167627254788453 · Twitter Post
• https://twitter.com/CVEnew/status/2053131401860640862 · Twitter Post
• https://twitter.com/VulmonFeeds/status/2053075543260606942 · Twitter Post
• https://t.me/cveNotify/163167 · Telegram Post
• https://t.me/CVEtracker/53187 · Telegram Post