CVE-2026-24983 in Core Plugin
Summary
by MITRE • 03/25/2026
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in UpSolution UpSolution Core us-core allows Reflected XSS.This issue affects UpSolution Core: from n/a through <= 8.41.
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Analysis
by VulDB Data Team • 03/31/2026
This cross-site scripting vulnerability exists within the UpSolution Core us-core plugin for WordPress, representing a classic reflected xss flaw that enables attackers to inject malicious scripts into web pages viewed by other users. The vulnerability occurs during the web page generation process when input parameters are not properly sanitized or escaped before being rendered back to users. This weakness allows an attacker to craft malicious URLs containing script code that gets executed in the victim's browser when the page is loaded, creating a persistent vector for malicious activity.
The technical implementation of this vulnerability stems from inadequate input validation and output escaping mechanisms within the plugin's codebase. When user-supplied data is processed and subsequently displayed in web pages without proper sanitization, it creates an opening for attackers to inject javascript code or other malicious payloads. The reflected nature of this vulnerability means that the malicious script is reflected back to the user through the web application's response, typically via url parameters or form inputs. This type of vulnerability falls under CWE-79 which specifically addresses cross-site scripting flaws in web applications.
The operational impact of this vulnerability extends beyond simple script execution as it can enable attackers to perform session hijacking, deface websites, steal user credentials, or redirect users to malicious sites. Attackers can craft specially designed URLs that, when clicked by unsuspecting users, will execute malicious code in their browsers. This could lead to unauthorized access to user accounts, data exfiltration, or the compromise of entire websites. The vulnerability affects versions from the initial release through version 8.41, indicating a long-standing issue that has not been adequately addressed in the plugin's security implementation.
Mitigation strategies should focus on implementing comprehensive input validation and output escaping mechanisms throughout the plugin's codebase. Developers must ensure that all user-supplied data is properly sanitized before being rendered in web pages, utilizing proper html escaping functions and context-appropriate encoding. The recommended approach involves implementing strict validation of input parameters and applying appropriate output encoding based on the context where the data will be displayed. Security measures should include the implementation of content security policies, proper header configuration, and regular security audits to identify and remediate similar vulnerabilities. This vulnerability aligns with several ATT&CK techniques including initial access through malicious links and privilege escalation via session hijacking, making it a critical concern for web application security. Organizations should also consider implementing web application firewalls and monitoring for suspicious traffic patterns that may indicate exploitation attempts.