GHSA-4v8w-gg5j-ph37 is a critical-severity (CVSS 9.1) CWE-305 vulnerability in mantisbt/mantisbt. A fix is available for mantisbt/mantisbt — see the affected versions and patch details below.
MantisBT vulnerable to authentication bypass for some passwords due to PHP type juggling
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- 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 GHSA-4v8w-gg5j-ph37.
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.
How urgent is this, really
GHSA-4v8w-gg5j-ph37 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 379,145 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
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
Due to an incorrect use of loose (==) instead of strict (===) comparison in the authentication code, PHP type juggling will cause interpretation of certain MD5 hashes as numbers, specifically those matching scientific notation.
Impact
On MantisBT instances configured to use the MD5 login method, user accounts having a password hash evaluating to zero (i.e. matching regex ^0+[Ee][0-9]+$) are vulnerable, allowing an attacker knowing the victim's username to login without knowledge of their actual password, using any other password having a hash evaluating to zero, for example comito5 (0e579603064547166083907005281618).
No password bruteforcing for individual users is needed, thus $g_max_failed_login_count does not protect against the attack.
Patches
Workarounds
Check the database for vulnerable accounts, and change those users' passwords, e.g. for MySQL:
SELECT username, email FROM mantis_user_table WHERE password REGEXP '^0+[Ee][0-9]+$'
References
Credits
Thanks to Harry Sintonen / Reversec for discovering and reporting the issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | mantisbt/mantisbt | all versions | 2.27.2composer require mantisbt/mantisbt:^2.27.2 |
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 2.27.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4v8w-gg5j-ph37 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 GHSA-4v8w-gg5j-ph37 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-4v8w-gg5j-ph37. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-4v8w-gg5j-ph37 in your dependencies?
O3 Security finds GHSA-4v8w-gg5j-ph37 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.