CVE-2026-34970: MantisBT information disclosure in bugnote revisions page

CVE-2026-34970 · Severity: medium · CVSS 4 · Published 2026-05-20

MantisBT, a popular open-source bug tracking system, contains a vulnerability where users can still view certain details of private issues even after their access has been revoked. Specifically, if a user previously authored a note on an issue, they can still access that note's revision history to see the private issue's ID and summary. This could lead to the unauthorized disclosure of sensitive project metadata or internal ticket titles.

Technologies: MantisBT Mantis Bug Tracker, mantisbt/mantisbt (Packagist). Vendors: MantisBT, Packagist.

Quick answers

Is CVE-2026-34970 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-34970 being exploited in the wild.
How severe is CVE-2026-34970?
Medium severity, with a CVSS score of 4, published 20 May 2026.
Which products and versions are affected?
MantisBT Mantis Bug Tracker <= 2.28.1; MantisBT <= 2.28.1; mantisbt/mantisbt (Packagist) <= 2.28.1, ECOSYSTEM:introduced=0,fixed=2.28.2.
Is there a fix for CVE-2026-34970?
Yes. mantisbt/mantisbt (Packagist): upgrade to 2.28.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-34970 attacked?
It is attacked over the network, in a web application.
Am I affected by CVE-2026-34970?
Check whether you run MantisBT Mantis Bug Tracker, MantisBT or mantisbt/mantisbt (Packagist) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • mantisbt/mantisbt (Packagist): upgrade to 2.28.2 or later
    composer require mantisbt/mantisbt:^2.28.2

Technical details

An information disclosure vulnerability exists in MantisBT due to improper access control on the Bugnote Revision page. When an issue is marked as private or a user's access to an issue is revoked, the system fails to restrict access to the revision history for users who were the original authors of notes (bugnotes) on that issue. By navigating to the revision page of their own previous notes, an unauthorized user can view the parent issue's ID and Summary metadata. The full body of the revisions remains protected, but the metadata leakage violates the privacy settings of the parent issue. This is fixed in version 2.28.2.

Affected products

  • MantisBT MantisBT <= 2.28.1

Identifiers

  • CVE-2026-34970
  • GHSA-crmx-4p49-46m2

Timeline

  • 2026-05-09: disclosed: Initial disclosure by researcher
  • 2026-05-11: advisory: GitHub Advisory published
  • 2026-05-20: other: NVD published date

References

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