CVE-2026-105090

Stored XSS via Custom Head Scripts in Formbricks

Published Oct 3, 2026 CVSS 4.0 · 5.1 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Formbricks
Formbricks formbricks
Vendors & Products Formbricks
Formbricks formbricks
Type Values Removed Values Added
Title Stored XSS via Custom Head Scripts in Formbricks
Type Values Removed Values Added
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.
Weaknesses CWE-863
References
Metrics cvssV4_0

{'score': 5.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Oct 5, 2026, 5:05 PM
Reserved
Oct 3, 2026, 1:59 AM
Status
Awaiting Analysis
Published
Oct 3, 2026, 2:17 AM
Modified
Oct 6, 2026, 4:08 PM