CVE-2026-103475
CVE-2026-103475 is a critical-severity vulnerability with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-489.
Key facts
- Severity: Critical (CVSS 3.x base score 9.1)
- CVSS v4: 9.3
- EPSS exploit prediction: 0% (32nd percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-489
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2026-103475?
- 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.
- How severe is CVE-2026-103475?
- CVE-2026-103475 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
- Is CVE-2026-103475 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-103475?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
- When was CVE-2026-103475 published?
- CVE-2026-103475 was published on 2026-09-30.
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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