yii2-starter-kit through 4.2.0 Debug and Gii Module Exposure

Advisories

yii2-starter-kit through 4.2.0 Debug and Gii Module Exposure

severity: critical
date: 9/30/2026
Affecting: yii2-starter-kit <= 4.2.0
CVE: CVE-2026-103475
CWE: CWE-489 Active Debug Code
CVSS: 9.3
CVSS V4 Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
References: GitHub Issue #797
https://github.com/yii-starter-kit/yii2-starter-kit
https://github.com/yii-starter-kit/yii2-starter-kit/blob/cc2c451e8c959c7300b04efea597706a38609f58/common/config/web.php#L21
Credit: Vikash Gupta
Description: yii2-starter-kit through 4.2.0 exposes the Yii debug and Gii modules to all IP addresses by setting allowedIPs to ['*'] in its default development configuration. Unauthenticated remote attackers can access the debug endpoint to read sensitive data including session cookies and database queries, or access the Gii endpoint to generate and write PHP files into the application directory.

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