CVE-2026-103474

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.

CVSS 4.0

8.7CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS 3.1

8.8CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS

0.4% chance of exploitation in the next 30 days; higher than 32% of CVEs (scores of 2026-10-25)

CWE

CWE-434

Published

2026-09-30

Modified

2026-09-30

Record from

the NVD, synced 2026-10-19

References

• https://github.com/yii-starter-kit/yii2-starter-kit
• https://github.com/yii-starter-kit/yii2-starter-kit/blob/cc2c451e8c959c7300b04efea597706a38609f58/backend/modules/file/controllers/StorageController.php#L36
• https://github.com/yii-starter-kit/yii2-starter-kit/issues/797
• https://www.vulncheck.com/advisories/yii2-starter-kit-through-4.2.0-unrestricted-file-upload-rce

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