CVE-2026-27639 Mercator vulnerable to stored XSS via unescaped Blade directives in display templates
Authenticated users can inject JavaScript via unescaped Blade directives, leading to code execution in other users' browsers.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-27639?
CVE-2026-27639 is a high-severity cross-site scripting vulnerability in dbarzin mercator, published on 25 Feb 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Mercator is an open source web application designed to enable mapping of information systems. A stored Cross-Site Scripting (XSS) vulnerability exists in Mercator prior to version 2026.02.22 due to the use of unescaped Blade directives (`{!! !!}`) in display templates. An authenticated user with the User role can inject arbitrary JavaScript payloads into fields such as "contact point" when creating or editing entities. The payload is then executed in the browser of any user who views the affected page, including administrators. Version 2026.02.22 fixes the vulnerability.
Weakness: CWE-79
Which versions are affected by CVE-2026-27639?
It affects 1 product.
Products include Sourcentis Mercator.
How do I fix CVE-2026-27639?
No fix has been published for CVE-2026-27639 yet. Limit exposure of the affected software until one is available.
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-2026-27639 being exploited?
There is no known exploitation of CVE-2026-27639 in the wild and no public exploit code.
Sources
Also known as GHSA-65p7-pph2-966g.