CVE-2026-42071: Mantisbt/mantisbt MantisBT Has A Private Bugnote Vulnerability

HIGH
Advisory Identifier: GHSA-pw5x-2mf9-3xc8
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CWE-862
Published
Advisory Summary

CVE-2026-42071 is a HIGH mantisbt has a private bugnote vulnerability (CWE-862: Missing Authorization) affecting Mantisbt/mantisbt libraries in the Packagist ecosystem. The issue involves mantisbt has a private bugnote attachment content leak via rest api. Remediation is available by upgrading affected packages to version 2.28.2.

CVE-2026-42071 at a Glance

CVE Identifier CVE-2026-42071
GHSA Identifier GHSA-pw5x-2mf9-3xc8
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-862: Missing Authorization
Affected Product Mantisbt/mantisbt
Package Ecosystem Packagist
Published Date
Last Updated

How to Fix CVE-2026-42071

To remediate this vulnerability, upgrade all affected Mantisbt/mantisbt dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

mantisbt/mantisbt fixed: 2.28.2 
Upgrade mantisbt/mantisbt to 2.28.2
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for mantisbt/mantisbt

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-42071, inspect your project dependencies for Mantisbt/mantisbt:

inspect dependencies for mantisbt/mantisbt

Analyze the terminal output to locate any version of Mantisbt/mantisbt in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.28.2), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-862: Missing Authorization, where the product does not perform an authorization check when an actor attempts to access a resource or perform an action. In Mantisbt/mantisbt, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

CVE-2026-42071 Affected Mantisbt/mantisbt Versions

1 component(s)
Fixed Versions:
2.28.2
Product / Package Ecosystem Affected Versions Fixed Version
mantisbt/mantisbt
 Packagist
≥ 2.23.0
< 2.28.2
2.28.2

References

GitHub Advisory / Wiki ADVISORY
https://github.com/mantisbt/mantisbt/security/advisories/GHSA-pw5x-2mf9-3xc8
NVD — CVE-2026-42071 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-42071
Security Fix Commit FIX COMMIT
https://github.com/mantisbt/mantisbt/commit/029d9d203d9e4ae96b3e59d552fa7395cc1e5071
GitHub Advisory / Wiki ADVISORY
https://github.com/advisories/GHSA-xjmx-cprh-646r
Mantisbt/mantisbt Source Repository REPOSITORY
https://github.com/mantisbt/mantisbt
mantisbt.org/bugs/view.php WEB
https://mantisbt.org/bugs/view.php?id=27039
mantisbt.org/bugs/view.php WEB
https://mantisbt.org/bugs/view.php?id=36985
mantisbt.org/bugs/view.php WEB
https://mantisbt.org/bugs/view.php?id=37092

Frequently Asked Questions

What is CVE-2026-42071?
CVE-2026-42071 is a security vulnerability in Mantisbt/mantisbt involving MantisBT has a Private Bugnote Attachment Content Leak via REST API under CWE-862: Missing Authorization.
Which Mantisbt/mantisbt versions are affected?
Affected versions include releases prior to 2.28.2 across affected packages: mantisbt/mantisbt.
What version fixes CVE-2026-42071?
Upgrading to 2.28.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is mantisbt/mantisbt affected?
Yes, mantisbt/mantisbt is affected in releases prior to 2.28.2. Upgrade your dependency to 2.28.2 or later.
What CWE is associated with CVE-2026-42071?
CVE-2026-42071 is classified under 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 can I check Packagist dependencies for CVE-2026-42071?
Run the dependency tree command: 'inspect dependencies for mantisbt/mantisbt'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-pw5x-2mf9-3xc8",
  "modified" : "2026-06-09T10:23:52Z",
  "published" : "2026-05-11T19:39:43Z",
  "aliases" : [ "CVE-2026-42071" ],
  "summary" : "MantisBT has a Private Bugnote Attachment Content Leak via REST API",
  "details" : "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.\n\n### Impact\n- REPORTER (access level 25) can view file attachments that were uploaded to private bugnotes by DEVELOPER/MANAGER/ADMIN users\n- Private bugnotes are intended for internal developer discussion; their attachments (logs, screenshots, patches) should be equally protected\n- The web UI is NOT affected — it filters through bugnote_get_all_visible_bugnotes() first\n\n### Patches\n- 029d9d203d9e4ae96b3e59d552fa7395cc1e5071\n\n### Workarounds\nNone\n\n### Credits\nThanks to the following security researchers for independently discovering and responsibly reporting the issue.\n- Vishal Shukla \n- Tristan Madani (@TristanInSec) from Talence Security \n- Tang Cheuk Hei (@siunam321) \n\nThis advisory's contents was largely copied from Tristan's well-written report.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "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"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "mantisbt/mantisbt"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.23.0"
      }, {
        "fixed" : "2.28.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 2.28.1"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/mantisbt/mantisbt/security/advisories/GHSA-pw5x-2mf9-3xc8"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-42071"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mantisbt/mantisbt/commit/029d9d203d9e4ae96b3e59d552fa7395cc1e5071"
  }, {
    "type" : "ADVISORY",
    "url" : "https://github.com/advisories/GHSA-xjmx-cprh-646r"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/mantisbt/mantisbt"
  }, {
    "type" : "WEB",
    "url" : "https://mantisbt.org/bugs/view.php?id=27039"
  }, {
    "type" : "WEB",
    "url" : "https://mantisbt.org/bugs/view.php?id=36985"
  }, {
    "type" : "WEB",
    "url" : "https://mantisbt.org/bugs/view.php?id=37092"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-862" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-11T19:39:43Z",
    "nvd_published_at" : "2026-05-28T21:16:30Z"
  }
}