CVE-2022-39357 is a high-severity (CVSS 8.1) CWE-1321 vulnerability in wintercms/winter. A fix is available for wintercms/winter — see the affected versions and patch details below.
Winter vulnerable to Prototype Pollution in Snowboard framework
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2022-39357 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
wintercms/winter🐘wintercms/winterReal-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
The Snowboard framework in affected versions is vulnerable to prototype pollution in the main Snowboard class as well as its plugin loader.
Patches
This issue has been patched in https://github.com/wintercms/winter/commit/2a13faf99972e84c9661258f16c4750fa99d29a1 (for 1.2) and https://github.com/wintercms/winter/commit/bce4b59584abf961e9400af3d7a4fd7638e26c7f (for 1.1) and is available with Winter v1.1.10 and v1.2.1.
Workarounds
If you have not yet upgraded, or are using the 1.1 branch of Winter (1.1.8 or above), you can avoid this issue by following some common security practices for JavaScript, including implementing a content security policy and auditing your scripts.
The 1.0 branch of Winter is not affected, as it does not contain the Snowboard framework.
For more information
If you have any questions or comments about this advisory:
- Email us at [email protected]
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | wintercms/winter | ≥ 1.1.8&&< 1.1.10 | 1.1.10composer require wintercms/winter:^1.1.10 |
| 🐘Packagist | wintercms/winter | ≥ 1.2.0&&< 1.2.1 | 1.2.1composer require wintercms/winter:^1.2.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for wintercms/winter, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update wintercms/winter to 1.1.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-39357 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2022-39357 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2022-39357. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2022-39357 in your dependencies?
O3 Security finds CVE-2022-39357 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.