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

> Authenticated users with administrateUsers permission can activate administrator accounts, leading to privilege escalation.

- **Severity:** High 7.1 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 8 Sep 2026
- **Updated:** 19 Sep 2026
- **Also known as:** GHSA-2j7x-j7rx-9x3g, GHSA-jqf5-vfg6-8cx5

## What is CVE-2026-86731?

CVE-2026-86731 is a high-severity vulnerability in craftcms cms, published on 8 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official 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.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2026-86731?


## How do I fix CVE-2026-86731?

No fix has been published for CVE-2026-86731 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-86731 being exploited?

There is no known exploitation of CVE-2026-86731 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-86731 and fix it if it is affected.

What it is: CVE-2026-86731 is a high-severity vulnerability in craftcms cms, published on 8 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-86731 in the wild and no public exploit code.

Affected product: craftcms cms. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-86731/ (Markdown: https://insights.sbomify.com/CVE-2026-86731/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-86731
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-86731
- OSV: https://osv.dev/vulnerability/CVE-2026-86731

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-86731/
Summaries are generated and may contain mistakes; the official description above is the record.