CVE-2026-42070: MantisBT authorization bypass in mc_issue_update API

Executive brief

MantisBT is a popular open-source bug tracking system used by organizations to manage software defects and project tasks. A security flaw allows lower-privileged users (Updaters) to modify or view private notes created by higher-privileged staff like Developers or Managers. This could lead to the exposure of confidential internal discussions or the unauthorized modification of project records.

Technical details

An incorrect authorization vulnerability (CWE-863) exists in the mc_issue_update() function of MantisBT. While the dedicated mc_issue_note_update() function correctly enforces a 'DEVELOPER' threshold, the general issue update API fails to properly validate permissions for bugnote modifications. This allows an authenticated attacker with 'UPDATER' privileges to edit notes, change time tracking data, and toggle the visibility of private notes belonging to higher-privileged users. The issue is addressed in version 2.28.2.

Affected products

• MantisBT MantisBT <= 2.28.1

Timeline

• 2026-05-09: disclosed
• 2026-05-11: advisory
• 2026-05-28: other: NVD published

References

• https://api.github.com/users/shukla304
• https://github.com/shukla304
• https://api.github.com/users/shukla304/gists%7B/gist_id%7D
• https://api.github.com/users/shukla304/repos
• https://avatars.githubusercontent.com/u/6738276?v=4
• https://api.github.com/users/shukla304/events%7B/privacy%7D