CVE-2026-103474

yii2-starter-kit through 4.2.0 Unrestricted File Upload RCE

8.7 High

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

0.39%Down 0.3 points since Oct 1, 2026

What each source reports

CVE List Score used8.7

yii2-starter-kit through 4.2.0 Unrestricted File Upload RCE

Record: CVE-2026-103474
CVSS 4.0: 8.7 HighCVSS: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: 8.8 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-434
Updated: 2026-11-02

EUVDEUVD-2026-902058.7

Record: EUVD-2026-90205
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-hfh8-jhpw-h99w8.7

yii2-starter-kit through 4.2.0 fails to validate file types in the backend storage upload actions...

Record: GHSA-hfh8-jhpw-h99w
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 8.8 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-434
Updated: 2026-11-02

NVD8.7

Record: CVE-2026-103474
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 8.8 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-434
Updated: 2026-11-02

OSV8.7

yii2-starter-kit through 4.2.0 Unrestricted File Upload RCE

Record: CVE-2026-103474
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Weakness: CWE-434
Updated: 2026-11-02

Affected products

yii2-starter-kit

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-103474 is a high vulnerability (CVSS 8.7) in Yii2-starter-kit, published September 30, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.39%, the 33rd percentile. No source names a fixed version.