CVE-2026-105090 Cross-site scripting in Formbricks
A lower-privileged user can inject malicious scripts via survey head scripts, executing arbitrary JavaScript in other users' sessions.
- 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-2026-105090?
CVE-2026-105090 is a medium-severity cross-site scripting vulnerability in Formbricks, published on 3 Oct 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
Formbricks before 5.4.4 and 6 before 6.0.1 allows stored XSS. The survey-level Custom Head Scripts feature did not enforce the documented Manage permission boundary. A workspace member holding only readWrite permission could configure Custom Head Scripts on a survey, an operation the documentation restricts to the Manage role. Because the configured scripts execute in the authenticated browser session of any user who opens the affected survey, a lower-privileged member can run arbitrary JavaScript (stored cross-site scripting) in the session of higher-privileged users. Fixed versions require Manage access to modify survey Custom Head Scripts.
Weakness: CWE-863
Which versions are affected by CVE-2026-105090?
How do I fix CVE-2026-105090?
No fix has been published for CVE-2026-105090 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-2026-105090 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-105090 exists.
Sources
Also known as GHSA-q9hg-xqvp-x2xv.