XSS in Craftcms Cms
CVE-2026-56393
Craft CMS 4.x (>= 4.0.0-RC1, < 4.17.0-beta.1) and 5.x (>= 5.0.0-RC1, < 5.9.0-beta.1) contain multiple stored cross-site scripting vulnerabilities where settings names and field option labels are rendered without sanitization (e.g., via the checkbox.twig template, which used {{ label|raw }}). An authenticated administrator (with allowAdminChanges enabled) can inject malicious payloads into section names, volume names, user group names, global set names, generated field names, checkbox/radio option labels, and custom source labels, causing arbitrary JavaScript to execute in other users' control-panel sessions. Fixed in 4.17.0-beta.1 and 5.9.0-beta.1.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (22.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 22nd percentile — 22.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
- Craftcms Cms — versions 5.0.0-RC1, 5.9.0-beta.1, 4.0.0-RC1
Weakness classification (CWE)
References
- github.com/craftcms/cms/security/advisories/GHSA-4mgv-366x-qxvx (vendor-advisory)
- github.com/craftcms/cms/commit/943152d2246b36f12adf161a03b8695b773d9276 (patch)
- github.com/craftcms/cms/commit/67780a778c6ec04e68e64a0b1177c168306144a2 (patch)
- www.vulncheck.com/advisories/craft-cms-multiple-stored-cross-site-scripting-in-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-56393?
- CVE-2026-56393 is a medium-severity vulnerability in Craftcms Cms, classified under Cross-site Scripting. CVSS score: 4.8/10. Published 2026-06-21.
- How severe is CVE-2026-56393?
- Medium severity. CVSS v3 base score is 4.8 out of 10.