statamic/cms security advisory

CVE-2026-27939: Statamic allows Authenticated Control Panel users to escalate privileges via elevated session bypass

CVE-2026-27939 is a high-severity privilege escalation vulnerability in the PHP package statamic/cms (CVSS 8.8), published 27 February 2026. It is fixed in 6.4.0; earlier versions are affected. Exploiting it needs a low-privilege user account.

high 8.8 published 2026-02-27 · updated 2026-06-17

Affected versions: >= 6.0.0, < 6.4.0
Fixed in: 6.4.0
Newest release: 6.40.0
Severity: High · CVSS 8.8
Type: Privilege escalation
CWE-287
Exploited in the wild: Not on the CISA KEV list
checked 2026-11-04

Is your statamic/cms version affected?

Run composer show statamic/cms in your project, then enter the version. We check it against this and every other known statamic/cms advisory.

Who can exploit CVE-2026-27939

Access: A normal, low-privilege user account in the app.

CVSS vector (scored by GitHub): CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Your app is only exposed if it uses the affected part of statamic/cms. The advisory below says which part that is. If you are not sure, upgrade anyway: it costs less than finding out.

How to fix CVE-2026-27939 in statamic/cms

Find the installed version: composer show statamic/cms. If you never required it yourself, composer why statamic/cms shows which package pulls it in.
Update it: composer update statamic/cms --with-all-dependencies. You need 6.4.0 or newer.
If Composer will not go that high, your composer.json constraint is holding it back. Widen it (for example "statamic/cms": "^6.4.0" if you can take that version), or upgrade the package that requires it.
Run composer audit. It reads the same advisory data and should no longer list CVE-2026-27939.
Commit composer.lock and deploy it. On the server, run composer install --no-dev from the lock file, not composer update.

If you cannot upgrade yet

General hardening for privilege escalation issues while the upgrade waits. None of it replaces the fix.

Remove accounts you do not need and review what each role can do.
Put the admin area behind a VPN, IP allow-list or extra login until you upgrade.
If your app does not use the affected feature, note that in your audit, but still plan the upgrade.

The CVE-2026-27939 advisory

Statmatic is a Laravel and Git powered content management system (CMS). Starting in version 6.0.0 and prior to version 6.4.0, Authenticated Control Panel users may under certain conditions obtain elevated privileges without completing the intended verification step. This can allow access to sensitive operations and, depending on the user’s existing permissions, may lead to privilege escalation. This has been fixed in 6.4.0.

Description from the CVE record, published by GitHub (the CVE Numbering Authority), via the NVD entry for CVE-2026-27939. Advisory title: “Statamic allows Authenticated Control Panel users to escalate privileges via elevated session bypass”.

References

GitHub advisory GHSA-rw9x-pxqx-q789 github.com
Fix commit 8639ef9 github.com

Other statamic/cms advisories

medium CVE-2026-71435: Statamic: Stored Cross-Site Scripting in Automagic Form Notification Email Template 2026-08-06
medium CVE-2026-71434: Statamic: Missing file upload validation on frontend forms allows uploading disallowed file types 2026-08-06
medium CVE-2026-64662: Statamic: Missing authorization on navigation endpoint allows disclosure of restricted entries 2026-08-06
medium CVE-2026-64663: Statamic: Unsafe method invocation via Antlers template resolution allows data destruction 2026-08-06
high CVE-2026-64665: Statamic: Account takeover via OAuth email matching without email-verification check 2026-08-06
medium CVE-2026-64664: Statamic: Missing authorization on Control Panel endpoint allows disclosure of user existence 2026-08-06

Need help patching or upgrading? Laskyr does PHP and Laravel security fixes and upgrades. Tell us what you run and we reply with a plan and a price.

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Where this data comes from

Affected and fixed versions: the Packagist security advisories API (GitHub Advisory Database and FriendsOfPHP), the same data composer audit uses. Synced 2026-11-03.
Description, score, weakness and references: NIST National Vulnerability Database (NVD), checked 2026-11-04. This product uses data from the NVD API but is not endorsed or certified by the NVD.
Exploited-in-the-wild status: the CISA Known Exploited Vulnerabilities catalog, checked 2026-11-04.
Compiled by Daniel Lasek at Laskyr from the sources above. The summary, “who can exploit it”, “how to fix it” and hardening sections are our plain-English reading of the record and are generated from it. The quoted description is the record's own text. Spot an error? Tell us.