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.

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Attack Requirements None

User Interaction Passive

Vulnerable System Confidentiality Impact Low

Vulnerable System Integrity Impact Low

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact Low

Subsequent System Integrity Impact Low

Subsequent System Availability Impact None

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Affected Vendors & Products

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Advisories

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Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/formbricks/formbricks/pull/9432 cve-icon cve-icon
https://github.com/formbricks/formbricks/releases/tag/5.4.4 cve-icon cve-icon
https://github.com/formbricks/formbricks/releases/tag/6.0.1 cve-icon cve-icon
https://www.sec4check.pl/blog/posts/cve-formbricks-broken-access-control-stored-xss-custom-head-scripts.html cve-icon cve-icon
History

Sat, 03 Oct 2026 04:15:00 +0000

Type Values Removed Values Added
Title Stored XSS via Custom Head Scripts in Formbricks

Sat, 03 Oct 2026 02:15:00 +0000

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'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-10-03T01:59:10.911Z

Reserved: 2026-10-03T01:59:10.142Z

Link: CVE-2026-105090

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-03T02:17:18.370

Modified: 2026-10-03T02:17:18.370

Link: CVE-2026-105090

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-03T04:00:12Z

Weaknesses