Unsanitized SVG Upload Enables Stored XSS in WordPress Plugin

The All in One Files Upload WordPress plugin before 2.0.17 adds SVG to the site's allowed upload types and does not sanitise uploaded files or verify the authenticity of its public upload requests, allowing unauthenticated users to store files containing active content which run in the site's origin when a victim opens them.

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 All in One Files Upload WordPress plugin before version 2.0.17 contains a critical stored cross-site scripting (XSS) vulnerability stemming from inadequate file validation and missing CSRF protections. By adding SVG to allowed upload types without sanitizing file contents or verifying request authenticity, the plugin permits unauthenticated attackers to upload malicious SVG files containing executable scripts. When site administrators or visitors open these files, the embedded JavaScript executes within the site's security origin, enabling session hijacking, credential theft, malware distribution, and administrative account compromise. This vulnerability affects any WordPress installation running the vulnerable plugin version, with no authentication barrier protecting the upload endpoint.

Casky's 323 mapped skills leverage Claude's extended reasoning to detect the attack chains associated with MITRE techniques TA0001 (Resource Development—creating malicious payloads) and TA0043 (Reconnaissance—identifying upload endpoints). Practitioners using Casky would observe detection patterns for: (1) CWE-79 signature matching on uploaded SVG files containing script tags or event handlers, (2) anomalous unauthenticated POST requests to upload endpoints, (3) file storage patterns where user-supplied content lands in web-accessible directories, and (4) behavioral indicators of stored XSS post-exploitation activity such as session token exfiltration or admin API calls. The platform's skill mapping enables practitioners to correlate file upload anomalies with downstream execution indicators, translating raw vulnerability data into actionable threat intelligence aligned with the MITRE ATT&CK framework.

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Casky Risk Score

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EPSS Probability

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Shodan Exposure

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GreyNoise Signal

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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-2026-85573.

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-2026-85573

Casky has 323 skills that investigate the attack patterns behind CVE-2026-85573. Run one and get CVSS-scored findings in 3 minutes.

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