CVE-2026-26059 Overview
CVE-2026-26059 is a Stored Cross-Site Scripting (XSS) vulnerability in ChurchCRM, an open-source church management system. In versions prior to 6.8.2, an authenticated user with permission to edit groups could store a malicious JavaScript payload that would execute when the group was viewed in the Group View interface. This vulnerability allows attackers to inject persistent malicious scripts that affect other users accessing the compromised group page.
Critical Impact
Authenticated attackers can inject persistent JavaScript code that executes in victims' browsers when viewing affected groups, potentially leading to session hijacking, credential theft, or further compromise of the ChurchCRM application.
Affected Products
- ChurchCRM versions prior to 6.8.2
Discovery Timeline
- 2026-02-19 - CVE CVE-2026-26059 published to NVD
- 2026-02-19 - Last updated in NVD database
Technical Details for CVE-2026-26059
Vulnerability Analysis
This vulnerability is classified as CWE-79 (Improper Neutralization of Input During Web Page Generation), commonly known as Cross-Site Scripting. The flaw exists in ChurchCRM's group management functionality, where user-supplied input is not properly sanitized before being rendered in the Group View page. When an authenticated user with group editing privileges submits malicious JavaScript code within group-related fields, the application stores this input without proper encoding or validation. Subsequently, when any user navigates to view the affected group, the stored malicious script executes within their browser context.
The attack requires network access and user interaction, as victims must navigate to the compromised group page for the payload to execute. The vulnerability primarily impacts the integrity and confidentiality of user sessions within the application's scope.
Root Cause
The root cause of this vulnerability is insufficient input validation and output encoding in the group editing functionality of ChurchCRM. The application fails to properly sanitize user-supplied data before storing it in the database and does not apply appropriate output encoding when rendering group information in the Group View interface. This allows malicious HTML and JavaScript content to be persisted and later executed in the context of other users' browser sessions.
Attack Vector
The attack is carried out over the network by an authenticated attacker who has been granted permissions to edit groups within ChurchCRM. The attacker crafts a malicious JavaScript payload and injects it into a group field (such as the group name or description). Once stored, any user who subsequently views the affected group will have the malicious script execute in their browser with the same privileges as their authenticated session.
The attacker could leverage this vulnerability to steal session cookies, redirect users to phishing pages, modify displayed content, or perform actions on behalf of the victim user within ChurchCRM. Since the payload is stored persistently, it will continue to affect users until the malicious content is removed or the system is patched.
Detection Methods for CVE-2026-26059
Indicators of Compromise
- Unusual JavaScript code or HTML tags present in group name or description fields in the ChurchCRM database
- Unexpected outbound network requests from client browsers when viewing group pages
- User reports of unexpected behavior or pop-ups when accessing the Group View functionality
- Audit logs showing modifications to group fields containing script tags or event handlers
Detection Strategies
- Implement Content Security Policy (CSP) headers and monitor for CSP violation reports indicating attempted XSS execution
- Deploy web application firewall (WAF) rules to detect and block common XSS patterns in HTTP requests
- Conduct regular database audits to identify suspicious content containing <script>, javascript:, onerror, or similar XSS vectors in group-related tables
- Review application access logs for unusual patterns of group editing followed by viewing from different user sessions
Monitoring Recommendations
- Enable detailed logging of all group creation and modification events within ChurchCRM
- Monitor for CSP violation events that may indicate blocked XSS attempts
- Set up alerts for database changes containing potentially malicious HTML or JavaScript content
- Implement browser-based detection solutions that can identify and report suspicious script execution
How to Mitigate CVE-2026-26059
Immediate Actions Required
- Upgrade ChurchCRM to version 6.8.2 or later immediately
- Review and audit existing group entries for any suspicious JavaScript or HTML content
- Temporarily restrict group editing permissions to trusted administrators until the patch is applied
- Implement Content Security Policy (CSP) headers to provide defense-in-depth against XSS attacks
Patch Information
ChurchCRM version 6.8.2 addresses this vulnerability by implementing proper input sanitization and output encoding for group-related fields. Organizations running affected versions should upgrade to 6.8.2 or later as soon as possible. For detailed patch information, refer to the GitHub Security Advisory.
Workarounds
- Restrict group editing permissions to a minimal set of highly trusted users until the patch can be applied
- Implement a web application firewall (WAF) with XSS filtering rules to block malicious payloads
- Deploy Content Security Policy (CSP) headers with strict script-src directives to mitigate the impact of any injected scripts
- Conduct manual review of all group entries to identify and remove any existing malicious content
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
