GHSA-pw5x-2mf9-3xc8 CVE-2026-42071

MantisBT has a Private Bugnote Attachment Content Leak via REST API

High Packagist

Severity: 0.0 / 10; High · CVSS 4.0
Exploit chance (EPSS): 0.26%; Chance of exploitation in the next 30 days. Higher than 17.80% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-862 Missing Authorization
Fix: 2.28.2; Upgrade mantisbt/mantisbt to this version or later

Description

A missing authorization check in MantisBT's file visibility function allows any authenticated user (REPORTER+) to download attachments on private bugnotes they should not be able to access, via the REST API endpoint GET /api/rest/issues/{id}/files and SOAP API mc_issue_attachment_get endpoint.

Impact

REPORTER (access level 25) can view file attachments that were uploaded to private bugnotes by DEVELOPER/MANAGER/ADMIN users
Private bugnotes are intended for internal developer discussion; their attachments (logs, screenshots, patches) should be equally protected
The web UI is NOT affected — it filters through bugnote_get_all_visible_bugnotes() first

Patches

029d9d203d9e4ae96b3e59d552fa7395cc1e5071

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
Tang Cheuk Hei (@siunam321)

This advisory's contents was largely copied from Tristan's well-written report.

Affected versions

Packagist

Package	Vulnerable	Fixed in
mantisbt/mantisbt	`>= 2.23.0, < 2.28.2`	`2.28.2`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

mantisbt/mantisbt Packagist → `2.28.2`

composer

composer require mantisbt/mantisbt:^2.28.2

Severity breakdown

CVSS 4.0 0.0

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:L/SC:N/SI:N/SA:N

Attack vector: Network
Attack complexity: Low
Attack requirements: None
Privileges required: Low
User interaction: None
Confidentiality (vulnerable system): High
Integrity (vulnerable system): Low
Availability (vulnerable system): Low
Confidentiality (subsequent systems): None
Integrity (subsequent systems): None
Availability (subsequent systems): None

Weakness

CWE-862: Missing Authorization

The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

How to prevent it

Architecture and Design: Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
Architecture and Design: Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor [REF-7].
Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
Architecture and Design: For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page. One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.
System Configuration, Installation: Use the access control capabilities of your operating system and server environment and define your access control lists accordingly. Use a "default deny" policy when defining these ACLs.

References

Advisories

Packages

github.com/mantisbt/mantisbt

Timeline

May 11, 2026 Published
Sep 10, 2026 Last updated by the source
Nov 1, 2026 Latest EPSS score

Advisory	Severity	Why it's related
GHSA-h2wf-967x-gxvw MantisBT: Stored XSS in print_all_bug_page_word.php	High	Also affects mantisbt/mantisbt
GHSA-4vpf-w7qv-5h3q MantisBT: Injection of TIME_TRACKING and REMINDER Notes via REST and SOAP APIs	Medium	Also affects mantisbt/mantisbt
GHSA-3v2j-6fw9-f57c MantisBT: REST and SOAP API Issue Update Accepts Unreleased Product Versions From Updaters	Medium	Also affects mantisbt/mantisbt
GHSA-vcrw-4xvv-jh49 MantisBT: Reflected XSS in admin/install.php via unescaped printf	Critical	Also affects mantisbt/mantisbt
GHSA-77x8-3v3h-hrhv MantisBT: Reflected XSS in admin/install.php	Critical	Also affects mantisbt/mantisbt
GHSA-m7ph-9558-mrx3 MantisBT: REST API unauthorized Issue status change	Medium	Also affects mantisbt/mantisbt
GHSA-v84x-qvhg-f36r MantisBT: Remote Code Execution via eval() Class Hoisting in adm_config_set.php	High	Also affects mantisbt/mantisbt
GHSA-c2xg-qjqw-2v98 MantisBT: SOAP API Authentication Bypass with Privilege Escalation to Administrator	Critical	Also affects mantisbt/mantisbt

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