How severe is CVE-2026-41128?

No CVSS score has been assigned to CVE-2026-41128 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-41128?

CVE-2026-41128 affects the following packages: craftcms/cms (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2026-41128?

Update craftcms/cms to 5.9.15 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-41128 is resolved across your whole dependency graph.

How do I detect CVE-2026-41128 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for craftcms/cms. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2026-41128 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-41128?

O3 pinpoints whether CVE-2026-41128 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2026-41128 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-41128 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was CVE-2026-41128 published, and has it been updated?

CVE-2026-41128 was published on April 21, 2026 and was last updated on August 7, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘 Packagist

CVE-2026-41128

Fix: craftcms/cms@b135384

CVE-2026-41128 is a security vulnerability in craftcms/cms. O3 Security confirms whether CVE-2026-41128 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Craft CMS has a Missing Authorization Check on User Group Removal via save-permissions Action

Also known asGHSA-jq2f-59pj-p3m3

Published

Apr 21, 2026

Updated

Aug 7, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Real-World Exposure

1 pkg affected

🐘craftcms/cms

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

Craft CMS is a content management system (CMS). In versions 5.6.0 through 5.9.14, the actionSavePermissions() endpoint allows a user with only viewUsers permission to remove arbitrary users from all user groups. While _saveUserGroups() enforces per-group authorization for additions, it performs no equivalent authorization check for removals, so submitting an empty groups value removes all existing group memberships. Version 5.9.15 contains a patch.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`craftcms/cms`	≥ 5.6.0&&< 5.9.15	5.9.15

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for craftcms/cms. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update craftcms/cms to 5.9.15 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-41128 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-41128 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2026-41128. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Craft CMS is a content management system (CMS). In versions 5.6.0 through 5.9.14, the `actionSavePermissions()` endpoint allows a user with only `viewUsers` permission to remove arbitrary users from all user groups. While `_saveUserGroups()` enforces per-group authorization for additions, it performs no equivalent authorization check for removals, so submitting an empty `groups` value removes all existing group memberships. Version 5.9.15 contains a patch.

O3 Security · Impact-Aware SCA

Is CVE-2026-41128 in your dependencies?

O3 detects CVE-2026-41128 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works