CVE-2026-42070 — mantisbt/mantisbt
Fix: mantisbt/mantisbt@6e58faeCVE-2026-42070 is a CWE-863 vulnerability in mantisbt/mantisbt. A fix is available for mantisbt/mantisbt — see the affected versions and patch details below.
MantisBT: Authorization Bypass in Bugnote Editing via Issue Update API
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-42070.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
mantisbt/mantisbtReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
The mc_issue_update() function in MantisBT allows users having update_bug_threshold access (UPDATER, with default settings) to edit, change view state, and modify time tracking on bugnotes belonging to other users — bypassing the default DEVELOPER (level 55) threshold required by the dedicated mc_issue_note_update() function.
Impact
- UPDATER can edit notes by DEVELOPER/MANAGER/ADMIN — bypassing the DEVELOPER threshold
- UPDATER can change private notes to public — exposing confidential internal discussion
- UPDATER can change public notes to private — hiding information from reporters/viewers
Patches
- 6e58fae4f22efdc3987f903c8ba2611de17a9435
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
This advisory's contents was largely copied from Tristan's well-written report.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | mantisbt/mantisbt | all versions | 2.28.2composer require mantisbt/mantisbt:^2.28.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mantisbt/mantisbt, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update mantisbt/mantisbt to 2.28.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-42070 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-42070 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-42070. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-42070 in your dependencies?
O3 Security finds CVE-2026-42070 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.