What’s Vulnerable › Vulnerabilities

CVE-2026-103475: yii2-starter-kit through 4.2.0 Debug and Gii Module Exposure

• Severity: critical (CVSS 9.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-30 · updated 2026-09-30
• Weakness: CWE-489

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.

Affected products

• yii2-starter-kit: through 4.2.0

References

• 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
• https://github.com/yii-starter-kit/yii2-starter-kit/issues/797
• https://www.vulncheck.com/advisories/yii2-starter-kit-through-4.2.0-debug-and-gii-module-exposure

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