CVE-2026-45627 Arcane: Unauthenticated reflected XSS via SVG color parameter in /api/app-images/logo enables admin account takeover

What is CVE-2026-45627?

CVE-2026-45627 is a high-severity cross-site scripting vulnerability in getarcaneapp arcane, published on 29 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

Arcane is an interface for managing Docker containers, images, networks, and volumes. Prior to 1.19.0, the unauthenticated GET /api/app-images/logo endpoint reflects a user-supplied color query parameter into the body of an SVG document via strings.ReplaceAll with no escaping. The substitution lands inside a <style> element of the embedded logo.svg, allowing an attacker to close the style block and inject executable <script> content. Because the response is served as image/svg+xml and Arcane sets no Content-Security-Policy or X-Content-Type-Options headers, navigating a logged-in admin victim to a crafted URL executes attacker-controlled JavaScript in Arcane's origin and rides the victim's HttpOnly JWT cookie to fully compromise the admin account. This vulnerability is fixed in 1.19.0.

Weakness: CWE-79

Which versions are affected by CVE-2026-45627?

3 open source packages ship an affected version, including github.com/getarcaneapp/arcane/backend.

How do I fix CVE-2026-45627?

Upgrade github.com/getarcaneapp/arcane/backend to 1.19.0 or later.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2026-45627 being exploited?

There is no known exploitation of CVE-2026-45627 in the wild and no public exploit code.

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-q2pj-8v84-9mh5, GO-2026-5561.