CVE-2026-54864 in Post Video Players Plugin
Summary
by MITRE • 10/29/2026
Unauthenticated Cross Site Scripting (XSS) in Post Video Players <= 1.165 versions.
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Analysis
by VulDB Data Team • 10/29/2026
The vulnerability identified as an unauthenticated cross-site scripting flaw within the Post Video Players plugin, specifically affecting versions up to and including 1.165, represents a significant security risk for WordPress-based websites that utilize this media management tool. This type of vulnerability arises when a web application fails to properly validate, sanitize, or encode user-supplied input before incorporating it into its dynamic content generation process. In the context of Post Video Players, attackers can inject malicious JavaScript code through various entry points within the plugin's interface, such as video URL fields, metadata inputs, or configuration settings that are accessible without requiring administrative privileges. Because the attack is unauthenticated, any visitor to the website, including anonymous users and search engine crawlers, has the ability to trigger this vulnerability, thereby expanding the potential blast radius significantly compared to authenticated-only flaws.
From a technical perspective, the core issue lies in the insufficient handling of special characters within user-controlled data streams. When the plugin processes input intended for video embedding or player configuration, it likely passes these values directly into HTML output contexts without applying appropriate encoding mechanisms such as HTML entity encoding or context-aware escaping. This allows an attacker to break out of the expected DOM structure and inject arbitrary script tags that execute in the victim's browser session under the security context of the targeted website. The execution environment is typically the same origin policy, meaning the malicious scripts have full access to cookies, local storage, session tokens, and other sensitive data associated with the user’s current login state on the site.
The operational impact of this vulnerability extends beyond mere defacement or visual disruption. Unauthenticated XSS attacks are frequently leveraged for credential harvesting through phishing techniques where a fake login form is injected into the page to capture usernames and passwords. Furthermore, attackers can utilize the compromised session to perform actions on behalf of legitimate users, such as modifying site settings, creating new administrative accounts, or deleting content if the victim has elevated privileges. In more sophisticated scenarios, this vulnerability serves as an initial foothold for further exploitation chains, potentially leading to remote code execution if combined with other server-side vulnerabilities or used to bypass security headers like Content Security Policy through script injection techniques that exploit misconfigurations in CSP directives.
This flaw aligns closely with Common Weakness Enumeration (CWE) identifiers such as CWE-79, which describes Improper Neutralization of Input During Web Page Generation commonly known as Cross-site Scripting. Additionally, the attack vector maps to MITRE ATT&CK techniques including T1059.007 for JavaScript execution and potentially T1204.002 for User Execution if social engineering is employed to lure victims into clicking malicious links that trigger the payload. The lack of authentication requirement places this vulnerability in a high-severity category according to most scoring systems, as it requires no prior access or privilege escalation to exploit.
Mitigation strategies must prioritize immediate remediation through software updates. Site administrators should upgrade Post Video Players to version 1.166 or later where the input validation and output encoding mechanisms have been corrected by the developers. Until an update is applied, temporary mitigations may include implementing a Web Application Firewall (WAF) rule set designed to detect and block common XSS payloads in HTTP request parameters associated with video player inputs. Additionally, enforcing strict Content Security Policy headers can help mitigate the impact of successful injection attempts by restricting the sources from which scripts are allowed to execute, although this is not a substitute for fixing the underlying code defect. Regular security audits and penetration testing should be conducted on all third-party plugins to ensure they adhere to secure coding standards and do not introduce similar vulnerabilities into the application ecosystem.