Is CVE-2026-34579 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-34579 being exploited in the wild.

How severe is CVE-2026-34579?

Medium severity, with a CVSS score of 4, published 19 May 2026.

Which products and versions are affected?

MantisBT >= 2.26.1, = 2.26.1, <= 2.28.1, ECOSYSTEM:introduced=2.26.1,fixed=2.28.2.

Is there a fix for CVE-2026-34579?

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-2026-34579 attacked?

It is attacked over the network, in a network appliance.

Am I affected by CVE-2026-34579?

Check whether you run 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.

CVE-2026-34579: MantisBT authorization bypass in private issue monitoring

Q: Is there a fix for CVE-2026-34579?

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.

Q: How is CVE-2026-34579 attacked?

It is attacked over the network, in a network appliance.

Q: Am I affected by CVE-2026-34579?

Check whether you run 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.

CVE-2026-34579 · Severity: medium · CVSS 4 · Published 2026-05-19

MantisBT is a popular open-source bug tracking system. A security flaw allows users with basic project access to bypass security restrictions and monitor private issues they are not authorized to see. While they cannot view the issue directly on the website, they will receive email notifications containing the private issue's details and updates, potentially exposing sensitive project information.

Technologies: MantisBT, mantisbt/mantisbt (Packagist). Vendors: MantisBT, Packagist.

Quick answers

Is CVE-2026-34579 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-34579 being exploited in the wild.
How severe is CVE-2026-34579?: Medium severity, with a CVSS score of 4, published 19 May 2026.
Which products and versions are affected?: MantisBT >= 2.26.1, <= 2.28.1; mantisbt/mantisbt (Packagist) >= 2.26.1, <= 2.28.1, ECOSYSTEM:introduced=2.26.1,fixed=2.28.2.
Is there a fix for CVE-2026-34579?: 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-2026-34579 attacked?: It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-34579?: Check whether you run 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 authorization bypass exists in bug_monitor_add.php due to improper validation of POST requests. An attacker with low-privileged project access can submit a crafted request to monitor a private issue; although the application returns an 'Access Denied' error, it still processes the request and establishes the monitoring relationship. While direct web access to the issue remains restricted, the attacker successfully triggers the notification system, receiving sensitive metadata and content via email. This vulnerability is addressed in version 2.28.2.

Affected products

MantisBT MantisBT >= 2.26.1, <= 2.28.1

Identifiers

CVE-2026-34579
GHSA-ggw7-9675-6v4v

Timeline

2026-05-09: disclosed
2026-05-11: advisory: GitHub Advisory published
2026-05-19: other: NVD published

References

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