Stored XSS via unescaped user group names
Published Jun 21, 2026 · Updated Jun 21, 2026
Stored XSS in Pixel & Tonic Craft CMS 5.0.0-RC1 through 5.8.21 allows remote authenticated users to run JavaScript in another user's browser. The User Permissions template inserts a stored user group name into the permissions section without HTML escaping, so embedded event-handler markup executes on rendering. Exploitation requires admin access, allowAdminChanges enabled, and another user to view or edit permissions; execution is confined to that user's browser context.
Summary
What happened
Stored XSS in Pixel & Tonic Craft CMS 5.0.0-RC1 through 5.8.21 allows remote authenticated users to run JavaScript in another user's browser. The User Permissions template inserts a stored user group name into the permissions section without HTML escaping, so embedded event-handler markup executes on rendering. Exploitation requires admin access, allowAdminChanges enabled, and another user to view or edit permissions; execution is confined to that user's browser context.
The record
- CVE
- CVE-2026-56381
- Published
- Jun 21, 2026
- Updated
- Jun 21, 2026
- Vendor
- Pixel & Tonic
- Product
- Craft CMS
- Classifications
- CWE-79, T1189
- Attack vector
- network
- Privileges
- admin
Timeline
How it unfolded
- Jun 21, 2026CVE publishedPublication date reported by the CVE source.
- Jun 21, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=5.0.0-RC1 <5.8.22
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Craft CMS User Permissions stored-XSS proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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