Stored XSS via Double-Encoded Entities in Video Titles

WWBN AVideo 12.4 through 29.2.0 contains a stored cross-site scripting vulnerability that allows authenticated uploaders to inject HTML by submitting doubly-encoded entities in video titles. Because safeString() strips tags before decoding entities and runs twice via setTitle() and save(), attackers can store markup that executes in trending, gallery, embed, and playlist pages.

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

WWBN AVideo versions 12.4 through 29.2.0 suffer from a stored cross-site scripting vulnerability with a CVSS score of 8.7, allowing authenticated uploaders to inject persistent malicious scripts through video titles. The vulnerability exploits a double-encoding bypass where the safeString() function strips HTML tags before decoding entities, but the encoding-decoding cycle happens twice during setTitle() and save() operations, leaving crafted payloads intact. This affects all users viewing trending videos, galleries, embeds, and playlists—making it a high-impact persistence mechanism for attackers with upload privileges who can compromise viewer sessions, steal credentials, or redirect traffic to malicious sites.

Casky.ai's 323 matched security skills map this attack pattern to MITRE ATT&CK techniques TA0001 (Initial Access) and TA0043 (Reconnaissance), enabling practitioners to identify suspicious encoding sequences and injection points. Using Claude's extended reasoning capabilities, the platform detects the telltale signature of double-encoded entities (%2526, &, etc.) in video metadata fields before persistence occurs. Practitioners using Casky would observe findings highlighting: (1) anomalous entity encoding chains in upload parameters, (2) tag-stripping bypass attempts in input validation logic, (3) XSS payload indicators in stored database content, and (4) unusual script execution contexts in frontend rendering—allowing teams to block uploads, patch validation functions, and implement output encoding before malicious content reaches end users.

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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-2026-105086.

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-2026-105086

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