CVE-2026-55790
HighCVSS 7.4Exploitation Probability (EPSS)
Low risk23th percentile — higher than 23% of all known CVEs
Summary
In Craft CMS versions 5.0.0-RC1 through 5.9.22 and 4.0.0-RC1 through 4.17.15, an attacker with only a GitHub account can inject a JavaScript payload into a craftcms/cms issue title. When a Craft admin uses the CraftSupport widget's 'Give feedback' screen and searches for a term that returns the poisoned issue, the payload executes in the admin's control panel session.
Risk Assessment
The risk is session hijacking without requiring a CMS panel account. An attacker could steal data, alter configuration, or deploy malware within the organization.
Recommendation
Immediately upgrade Craft CMS to version 4.17.16 or 5.9.23, which contain the fix. After updating, verify that the CraftSupport widget does not display suspicious issues.
Original NVD description (English source)
Craft CMS is a content management system (CMS). In versions 5.0.0-RC1 through 5.9.22 and 4.0.0-RC1 through 4.17.15, an attacker with only a GitHub account can plant a JavaScript payload in a craftcms/cms issue title. When a Craft admin uses the CraftSupport widget’s "Give feedback" screen and types a search term that returns the poisoned issue, the payload executes in the admin’s control panel session. No control panel account or elevated privileges are required on the attacker’s side. This issue has been fixed in versions 4.17.16 and 5.9.23.

