Vulnerability · Published Sep 30, 2026 · Assigned by VulnCheck
CVE-2026-103474yii2-starter-kit through 4.2.0 Unrestricted File Upload RCE
High 8.8
In plain English
A high-severity unrestricted file upload in yii2-starter-kit from yii2-starter-kit. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities).
Severity (CVSS 3.1)8.8High
Exploit odds (30 days)0.4%top 66.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
yii2-starter-kit through 4.2.0 fails to validate file types in the backend storage upload actions, allowing authenticated managers to upload PHP files. Attackers with manager role can upload PHP scripts to the web-accessible storage directory and request them to execute arbitrary code on the server.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| yii2-starter-kit | yii2-starter-kit | 0 – through 4.2.0 |
Weakness: CWE-434 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
References
- GitHub Issue #797 issue-tracking
- https://github.com/yii-starter-kit/yii2-starter-kit product
- https://github.com/yii-starter-kit/yii2-starter-kit/blob/cc2c451e8c959c7300b04efea597706a38609f58/backend/modules/file/controllers/StorageController.php#L36 technical-description
- VulnCheck Advisory: yii2-starter-kit through 4.2.0 Unrestricted File Upload RCE third-party-advisory