Winter vulnerable to privilege escalation by authenticated backend usersGHSA-pgpf-m8m4-6cg6
CRITICALGHSA-pgpf-m8m4-6cg6 is a critical-severity (CVSS 9.9) CWE-284 vulnerability in winter/wn-backend-module. A fix is available for winter/wn-backend-module — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-pgpf-m8m4-6cg6.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
winter/wn-backend-module🐘winter/wn-backend-module🐘winter/wn-backend-moduleReal-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
Impact
Affected versions of Winter CMS allowed authenticated backend users to escalate their accounts level of access to the system by modifying the roles / permissions assigned to their account through specially crafted requests to the backend while logged in.
To actively exploit this security issue, an attacker would need access to the Backend with a user account with any level of access.
The Winter CMS maintainers strongly recommend that all Winter CMS sites that have any reliance on the roles & permissions system to update immediately. Security fixes have been backported to all major versions of Winter (1.0, 1.1, and 1.2).
Patches
Multiple fixes and defence in depth has been applied to prevent current and future privilege escalation attacks at the lowest level possible.
This security issue has been fixed as of https://wintercms.com/releases/v1.0.477, https://wintercms.com/releases/v1.1.12, https://wintercms.com/releases/v1.2.12.
Workarounds
If you cannot upgrade, you may apply the changes from the releases to your Winter CMS installation manually to resolve this issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | winter/wn-backend-module | ≥ 1.2.0&&< 1.2.12 | 1.2.12composer require winter/wn-backend-module:^1.2.12 |
| 🐘Packagist | winter/wn-backend-module | ≥ 1.1.0&&< 1.1.12 | 1.1.12composer require winter/wn-backend-module:^1.1.12 |
| 🐘Packagist | winter/wn-backend-module | all versions | 1.0.477composer require winter/wn-backend-module:^1.0.477 |
Affected Products
winterwintercmsDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for winter/wn-backend-module, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update winter/wn-backend-module to 1.2.12 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-pgpf-m8m4-6cg6 is resolved across your whole dependency graph.
Workarounds
Close the privilege gap rather than the entry point: audit which accounts, roles and service identities can reach the affected operation, drop the component to the least privilege it actually needs, and review file and directory permissions created by earlier installs — a default left in place is what makes this reachable.
Frequently Asked Questions
Is GHSA-pgpf-m8m4-6cg6 in your dependencies?
Find it across Packagist, including transitive dependencies.