CVE-2026-78073 Overview
CVE-2026-78073 is a reflected cross-site scripting (XSS) vulnerability in the All Video Share Joomla extension developed by mrvinoth.com. The flaw affects versions 1.0.0 through 4.5.0. Multiple user-supplied inputs lack proper output escaping, enabling attackers to inject and reflect arbitrary JavaScript into rendered pages. The weakness is classified under CWE-79: Improper Neutralization of Input During Web Page Generation. Successful exploitation requires user interaction, such as clicking a crafted link, but no authentication or privileges. The issue impacts confidentiality, integrity, and availability at a limited scope within the victim's browser session.
Critical Impact
Attackers can execute arbitrary JavaScript in a victim's browser session, enabling session theft, credential harvesting, and site defacement against Joomla sites running All Video Share 1.0.0 through 4.5.0.
Affected Products
- Joomla Extension: All Video Share by mrvinoth.com
- Affected versions: 1.0.0 through 4.5.0
- Joomla CMS installations with the vulnerable extension enabled
Discovery Timeline
- 2026-08-28 - CVE-2026-78073 published to NVD
- 2026-08-28 - Last updated in NVD database
Technical Details for CVE-2026-78073
Vulnerability Analysis
The All Video Share extension processes several user-supplied parameters without escaping them before reflecting the values in HTTP responses. When a victim requests a URL containing attacker-controlled input, the extension embeds the payload directly into the HTML response. The browser then parses the injected markup as executable script.
Reflected XSS in a Joomla front-end extension expands the attack surface for any site that installs the plugin. Attackers can pivot from the reflection primitive to session hijacking, forced administrative actions via CSRF chaining, and phishing overlays on trusted domains.
Root Cause
The root cause is missing output encoding on multiple request parameters handled by the extension. Joomla provides helper functions such as htmlspecialchars() and the JOutput filtering API, but the vulnerable code paths write untrusted data directly into the response body. The absence of contextual escaping in HTML, attribute, and JavaScript contexts allows payloads to break out of the intended data context.
Attack Vector
Exploitation is network-based and requires user interaction. An attacker crafts a URL targeting a vulnerable All Video Share endpoint with a JavaScript payload embedded in a susceptible parameter. The attacker delivers the link through email, chat, or a malicious page. When the victim opens the link, the reflected payload executes in the origin of the Joomla site.
No verified proof-of-concept code is publicly available. Refer to the All Video Share extension homepage for vendor updates and technical details on the affected parameters.
Detection Methods for CVE-2026-78073
Indicators of Compromise
- Web server access logs containing URL parameters with encoded <script>, onerror=, onload=, or javascript: sequences directed at All Video Share endpoints.
- Unexpected outbound requests from user browsers to attacker-controlled domains following visits to Joomla pages hosting the extension.
- Session tokens or administrator cookies appearing in referer headers or third-party log sources.
Detection Strategies
- Deploy Web Application Firewall (WAF) rules that flag reflected script payloads on query strings and POST bodies targeting Joomla component routes such as index.php?option=com_allvideoshare.
- Correlate anomalous parameter lengths and character sets (angle brackets, backticks, entity encoding) against baseline traffic for the affected extension.
- Review Joomla error logs and PHP logs for parsing anomalies triggered by malformed payloads probing input fields.
Monitoring Recommendations
- Enable Content Security Policy (CSP) reporting endpoints and monitor report-uri submissions for inline-script violations originating from extension URLs.
- Alert on administrative session activity following clicks on external referrers, which can indicate successful session theft.
- Track version banners and file hashes of com_allvideoshare components to confirm patch status across the estate.
How to Mitigate CVE-2026-78073
Immediate Actions Required
- Identify all Joomla instances running All Video Share versions 1.0.0 through 4.5.0 and prioritize them for remediation.
- Restrict public access to affected endpoints via WAF rules or IP allow-listing until a fixed release is deployed.
- Rotate administrator sessions and reset credentials for accounts that recently interacted with untrusted links.
Patch Information
At the time of publication, no fixed version is referenced in the NVD entry. Consult the All Video Share extension homepage for vendor release notes and apply the first version above 4.5.0 that documents an XSS fix. Verify the update by re-testing the previously vulnerable parameters with encoded payloads.
Workarounds
- Disable or unpublish the All Video Share component in the Joomla Extension Manager until a patched version is installed.
- Enforce a strict Content Security Policy that blocks inline scripts and restricts script sources to trusted origins.
- Enable HTTPOnly and SameSite=Strict attributes on Joomla session cookies to limit the impact of script execution.
- Deploy generic reflected XSS signatures at the WAF layer covering com_allvideoshare request paths.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
