Auth bypass in Craftcms Cms
CVE-2026-86731
Craft CMS versions 5.0.0-RC1 through 5.10.11 are missing an admin-target guard in UsersController::actionActivateUser (the users/activate-user action). While the action requires the administrateUsers permission, it does not call requireAdmin() when the targeted user is an administrator, unlike the mirror action actionDeactivateUser. As a result, an authenticated control panel user who is not an administrator but holds the administrateUsers permission can activate a pending or deliberately deactivated administrator account, which can lead to permission escalation when combined with resetting that account's password. The issue is fixed in Craft CMS 5.10.12.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.003 (22.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 22.8% 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
Weakness classification (CWE)
References
- github.com/craftcms/cms/security/advisories/GHSA-jqf5-vfg6-8cx5 (vendor-advisory)
- www.vulncheck.com/advisories/craft-cms-5.0.0-rc1-before-5.10.12-permission-esca… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-86731?
- CVE-2026-86731 is a medium-severity vulnerability in Craftcms Cms, classified under Missing Authorization. CVSS score: 6.5/10. Published 2026-09-08.
- How severe is CVE-2026-86731?
- Medium severity. CVSS v3 base score is 6.5 out of 10.