Summary
The mc_issue_update() function in MantisBT allows users having update_bug_threshold access (UPDATER, with default settings) to edit, change view state, and modify time tracking on bugnotes belonging to other users, bypassing the default DEVELOPER (level 55) threshold required by the dedicated mc_issue_note_update() function.
Workarounds
None
Credits
Thanks to the following security researchers for independently discovering and responsibly reporting the issue.
- Vishal Shukla
- Tristan Madani (@TristanInSec) from Talence Security
This advisory's contents was largely copied from Tristan's well-written report.
Impact
- UPDATER can edit notes by DEVELOPER/MANAGER/ADMIN, bypassing the DEVELOPER threshold
- UPDATER can change private notes to public, exposing confidential internal discussion
- UPDATER can change public notes to private, hiding information from reporters/viewers
The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions. Typical impact: unauthorized data access or execution of privileged operations.
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
- 6e58fae4f22efdc3987f903c8ba2611de17a9435
Frequently Asked Questions
- What is CVE-2026-42070? CVE-2026-42070 is a medium-severity incorrect authorization vulnerability in mantisbt/mantisbt (composer), affecting versions <= 2.28.1. It is fixed in 2.28.2. The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions.
- Which versions of mantisbt/mantisbt are affected by CVE-2026-42070? mantisbt/mantisbt (composer) versions <= 2.28.1 is affected.
- Is there a fix for CVE-2026-42070? Yes. CVE-2026-42070 is fixed in 2.28.2. Upgrade to this version or later.
- Is CVE-2026-42070 exploitable, and should I be worried? Whether CVE-2026-42070 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-2026-42070 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-2026-42070? Upgrade
mantisbt/mantisbtto 2.28.2 or later.