CVE-2026-52307 in ClassCMS
Summary
by MITRE • 09/08/2026
An authenticated stored cross-site scripting (XSS) vulnerability in the Column Management component of ClassCMS 1CMS v5.6 allows attackers to execute arbitrary web scripts or HTML via injecting a crafted payload into the title field.
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Analysis
by VulDB Data Team • 09/08/2026
The identified security flaw resides within the Column Management subsystem of ClassCMS version 1CMS, specifically affecting release v5.6. This vulnerability is classified as an authenticated stored cross-site scripting issue, which indicates that successful exploitation requires the attacker to possess valid credentials for a user account with sufficient privileges to access and modify column configurations. Unlike reflected XSS attacks where malicious scripts are executed immediately upon request processing, this type of vulnerability involves persisting the injected payload within the application's data store, typically a database or file system. The specific point of injection is the title field associated with column management entries, suggesting that any user input intended for naming or labeling columns is processed without adequate sanitization or encoding before being stored and subsequently rendered in web pages accessible to other users.
From a technical perspective, the root cause lies in insufficient validation of special characters within the title parameter during both storage and retrieval phases. When an authenticated administrator or authorized user submits a column title containing malicious JavaScript code, the application fails to escape HTML entities such as less-than signs, greater-than signs, ampersands, or quotes. Consequently, when this data is later retrieved from the backend and displayed in the browser interface of other users viewing the site's content structure, the web browser interprets the injected script as legitimate executable code rather than static text. This behavior violates fundamental security principles regarding input validation and output encoding, allowing an attacker to bypass same-origin policy restrictions and execute arbitrary commands within the context of the victim's session.
The operational impact of this vulnerability is significant due to its stored nature and authentication requirement. Because the payload persists in the database, every user who accesses a page displaying the compromised column title will trigger the execution of the malicious script without any additional interaction from the attacker beyond the initial injection. This can lead to severe consequences including session hijacking through cookie theft, credential harvesting via fake login forms injected into the DOM, defacement of the website interface, or redirection of users to phishing sites. Furthermore, if the application integrates with third-party services or has elevated privileges for certain administrative functions, an attacker could potentially leverage the victim's authenticated session to perform unauthorized actions such as modifying site settings, deleting content, or escalating privileges within the CMS environment.
In terms of industry standard classifications, this vulnerability aligns with CWE-79 Improper Neutralization of Input During Web Page Generation commonly known as Cross-site Scripting. Specifically, it falls under the sub-category of Stored XSS where malicious scripts are permanently stored on target servers. From a tactical perspective related to the MITRE ATT&CK framework, this exploit maps to techniques involving Client-side Injection and potentially Credential Access if session tokens or cookies are exfiltrated. The requirement for authentication places this vulnerability in a higher severity tier compared to unauthenticated variants because it limits the attack surface to insider threats or compromised accounts but increases the potential damage per successful exploitation event due to the trusted context of the victim's browser session.
Mitigation strategies must address both immediate remediation and long-term defensive posture improvements. The primary technical fix involves implementing strict input validation on the title field in the Column Management component, ensuring that only expected alphanumeric characters and safe punctuation are accepted while rejecting or encoding any HTML special characters. Additionally, output encoding should be applied consistently whenever user-supplied data is rendered into HTML contexts to prevent browser interpretation of injected scripts as executable code. Developers should also consider implementing Content Security Policy headers to restrict the sources from which scripts can be loaded, thereby mitigating the impact even if an injection occurs. Regular security audits and penetration testing focused on input handling in administrative interfaces are recommended to identify similar flaws across other components of the CMS before they can be exploited by malicious actors seeking to compromise system integrity or user data confidentiality.