WordPress YAHMAN Plugin Arbitrary PHP File Upload

The YAHMAN Add-ons WordPress plugin before 0.9.31 does not validate the type of the remote files it caches in a publicly accessible directory, allowing unauthenticated attackers to write arbitrary PHP files on the server and achieve RCE when the relevant feature is enabled.

Casky was already ahead

This CVE exploits attack patterns that Casky's 323matched skills already investigate — long before this vulnerability was disclosed. Claude's reasoning model maps these techniques to MITRE ATT&CK, so practitioners who ran these skills have already seen the threat behaviour in their findings.

Analysis

The YAHMAN Add-ons WordPress plugin before version 0.9.31 contains a critical file validation vulnerability that allows unauthenticated attackers to upload arbitrary PHP files to publicly accessible directories. The plugin fails to validate the file types of remote files it caches, creating a direct path to Remote Code Execution (RCE). Any WordPress installation running the vulnerable plugin version with caching enabled becomes a target for attackers seeking to establish persistent access. This vulnerability affects website administrators and hosting providers equally, as compromised sites can be weaponized for further attacks across shared infrastructure.

Casky's 323 mapped skills detect the attack patterns underlying this vulnerability by analyzing MITRE ATT&CK techniques TA0001 (Reconnaissance) and TA0043 (Resource Development). Claude's extended reasoning identifies suspicious patterns such as: unauthenticated file write operations to web-accessible directories, PHP file creation outside normal plugin directories, unexpected process spawning from web server processes, and anomalous outbound connections from cached file execution. Practitioners using Casky would observe findings highlighting arbitrary file upload attempts, improperly validated input streams targeting the caching mechanism, and execution patterns consistent with web shell deployment. The skill set correlates these indicators across file system monitoring, web server logs, and process execution chains to surface the exploitation sequence before RCE completes.

Live Threat IntelligenceComing soon

Casky Risk Score

—

EPSS Probability

—

Shodan Exposure

—

GreyNoise Signal

—

Composite risk scoring from EPSS, CISA KEV, Shodan, and GreyNoise — 21 security APIs correlated into a single Casky Risk Score. Coming in Casky Pro. Join early access →

323 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-75799.

Abuse of Public-Facing API: Mobile API Abuse

mobile security · low

Run

abusing-dpapi-for-credential-access

red teaming · high

Run

abusing-shadow-credentials-for-privesc

red teaming · high

Run

MITRE ATT&CK Techniques

TA0001 TA0043

Investigate the attack patterns behind CVE-2026-75799

Casky has 323 skills that investigate the attack patterns behind CVE-2026-75799. Run one and get CVSS-scored findings in 3 minutes.

Run the skill that detects this →

X Instagram LinkedIn