Cross-site scripting in Craft CMS - CVE-2026-55790
Published: June 16, 2026
Vulnerability identifier: #VU134673
CSH Severity: Medium
CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
CVE-ID: CVE-2026-55790
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary JavaScript in an administrator's control panel session.
The vulnerability exists due to cross-site scripting in CraftSupportWidget.js when rendering GitHub issue titles returned by the GitHub API in the CraftSupport widget's "Give feedback" search results. A remote attacker can create a crafted GitHub issue title to execute arbitrary JavaScript in an administrator's control panel session.
User interaction is required: an administrator must use the CraftSupport widget's "Give feedback" screen and enter a search term that returns the crafted issue.
Affected software
Craft CMS
How to mitigate CVE-2026-55790
Install security update from vendor's website.
Craft CMS - addressed in versions 4.17.16, 5.9.23