Cyber Resilience

CVE-2026-39850

High

Published: 20 May 2026

Published
20 May 2026
Modified
21 May 2026
KEV Added
Patch
CVSS Score v3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS Score 0.0044 35.2th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-39850 is a high-severity Improper Input Validation (CWE-20) vulnerability. Its CVSS base score is 7.4 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 35.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Yii 2 is a PHP application framework. Versions 2.0.54 and prior contain flawed logic in the core view rendering method View::renderPhpFile() that leads to Local File Inclusion. The function calls extract($_params_, EXTR_OVERWRITE) before the require statement that loads the view…

more

file. As a result, a caller-controlled _file_ key in the $params array overwrites the internal local variable specifying which file to include, potentially enabling RCE if an attacker can write PHP files through a separate primitive, as well as information disclosure. This issue has been fixed in version 2.0.55.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
Why these techniques?

LFI in web framework enables public app exploitation for file read/disclosure; RCE conditional on separate write primitive.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v18.1

CVEs Like This One

CVE-2025-58901Shared CWE-98
CVE-2026-28020Shared CWE-98
CVE-2025-58940Shared CWE-98
CVE-2025-49362Shared CWE-98
CVE-2025-69046Shared CWE-98
CVE-2025-64373Shared CWE-98
CVE-2025-58899Shared CWE-98
CVE-2025-49383Shared CWE-98
CVE-2025-58936Shared CWE-98
CVE-2026-28089Shared CWE-98

Affected Assets

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-20

Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.

addresses: CWE-20

Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.

addresses: CWE-20

Directly implements checks on information inputs to reject invalid data before processing.

addresses: CWE-20

Spam protection mechanisms perform filtering and detection on inbound/outbound messages, directly compensating for missing or weak input validation of unsolicited content.

References