What is CVE-2022-39357?

CVE-2022-39357 is a high-severity vulnerability in Wintercms Winter, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 8.1/10. Published 2022-10-26.

How severe is CVE-2022-39357?

High severity. CVSS v3 base score is 8.1 out of 10.

Prototype Pollution in Wintercms Winter

CVE-2022-39357

Winter is a free, open-source content management system based on the Laravel PHP framework. The Snowboard framework in versions 1.1.8, 1.1.9, and 1.2.0 is vulnerable to prototype pollution in the main Snowboard class as well as its plugin loader. The 1.0 branch of Winter is not affected, as it does not contain the Snowboard framework. This issue has been patched in v1.1.10 and v1.2.1. As a workaround, one may avoid this issue by following some common security practices for JavaScript, including implementing a content security policy and auditing scripts.

Vulnerability class: Prototype Pollution

Published 2022-10-26 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.011 (64.7th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 65th percentile — 64.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: 0.000

Affected products

Wintercms Winter — versions = 1.2.0, >= 1.1.8, < 1.1.10, 1.1.8

Weakness classification (CWE)

CWE-1321 — Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution)

References

github.com/wintercms/winter/security/advisories/GHSA-3fh5-q6fg-w28q (Patch, Third Party Advisory)
github.com/wintercms/winter/commit/2a13faf99972e84c9661258f16c4750fa99d29a1 (Patch, Third Party Advisory)
github.com/wintercms/winter/commit/bce4b59584abf961e9400af3d7a4fd7638e26c7f (Patch, Third Party Advisory)
github.com/wintercms/winter/releases/tag/v1.1.10 (Third Party Advisory, Release Notes)
github.com/wintercms/winter/releases/tag/v1.2.1 (Third Party Advisory, Release Notes)

Frequently asked questions

What is CVE-2022-39357?: CVE-2022-39357 is a high-severity vulnerability in Wintercms Winter, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 8.1/10. Published 2022-10-26.
How severe is CVE-2022-39357?: High severity. CVSS v3 base score is 8.1 out of 10.