Summary
Using a crafted POST request to bug_monitor_add.php, a user with project-level access can add themselves as a monitor for a private issue they do not have access to. Despite displaying an Access Denied error, the application accepts the request and creates a monitor relationship for the private issue.
Workarounds
None
Credits
Thanks to Vishal Shukla for discovering and responsibly reporting the issue.
Impact
Direct access to the private issue remains blocked, but the user will receive email notifications for updates, leading to disclosure of the private issue's metadata and content.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
- 0a93267deba445fb9d15250c16e6fdb1246ffa65
Frequently Asked Questions
- What is CVE-2026-34579? CVE-2026-34579 is a medium-severity security vulnerability in mantisbt/mantisbt (composer), affecting versions >= 2.26.1, <= 2.28.1. It is fixed in 2.28.2.
- Which versions of mantisbt/mantisbt are affected by CVE-2026-34579? mantisbt/mantisbt (composer) versions >= 2.26.1, <= 2.28.1 is affected.
- Is there a fix for CVE-2026-34579? Yes. CVE-2026-34579 is fixed in 2.28.2. Upgrade to this version or later.
- Is CVE-2026-34579 exploitable, and should I be worried? Whether CVE-2026-34579 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-34579 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-34579? Upgrade
mantisbt/mantisbtto 2.28.2 or later.