Advisory details:
github_osv / GHSA-frf7-jhp9-jxm6
| Advisory ID | github_osv/GHSA-frf7-jhp9-jxm6 |
| Aliases |
CVE-2026-34390
|
| Summary | MantisBT Vulnerable to Privilege Escalation from Manager to Administrator Insufficient access control checks in _ProjectUsersAddCommand_ (used in *manage_proj_user_add.php* and REST API endpoint `PUT /project/{id}/users`) allows users having *manage_project_threshold* access level (*manager* by default) to grant project-level *administrator* access to any user (including themselves) in any Project they have *manager* rights in. The normal project-user add form does restrict the selectable access levels to the actor's own project role or below. However, the backend handler still accepts a forged higher access_level value and writes it. ### Impact Privilege escalation. The consequences of the privilege escalation are not as bad as it may sound, because having *administrator* access at Project level is effectively not very different from being *manager*, it does not actually give administrator privileges on the whole MantisBT instance. In particular, it does not let the upgraded user delete the Project or grant them any access to global administrative functions such as managing Users, Projects, Plugins, Custom Fields, etc. ### Patches - 69e0180f180ed5acf48a8d281a73683a7bf32461 ### Workarounds None ### Credits Thanks to the following security researchers for independently discovering and responsibly reporting the issue: - [Dracosec Research Limited](https://dracosec.tech/) (Siu Nam Tang, Chris Chan, Krecendo Hui, William Lam) - Vishal Shukla |
| Status | Published |
| Exploitability | 0.5 |
| Weighted Severity | 4.6 |
| Risk | 2.3 |
| Affected and Fixed Packages | Package Details |
| Introduced and Fixed Package Commit Patches | Package Commit Patches Details |
| CWE-284 | Improper Access Control |
| System | Score | Found at |
|---|---|---|
| cvssv4 | 5.1 | https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-frf7-jhp9-jxm6/GHSA-frf7-jhp9-jxm6.json |
| generic_textual | MODERATE |
No EPSS data available for this advisory.
| Patch URL | |
|---|---|
| There are no known patches. | |
| Attack Vector (AV) | Attack Complexity (AC) | Attack Requirements (AT) | Privileges Required (PR) | User Interaction (UI) | Vulnerable System Impact Confidentiality (VC) | Vulnerable System Impact Integrity (VI) | Vulnerable System Impact Availability (VA) | Subsequent System Impact Confidentiality (SC) | Subsequent System Impact Integrity (SI) | Subsequent System Impact Availability (SA) |
|---|---|---|---|---|---|---|---|---|---|---|
network adjacent local physical |
low high |
none present |
none low high |
none passive active |
high low none |
high low none |
high low none |
high low none |
high low none |
high low none |
Vector: SSVCv2/E:P/A:Y/T:P/P:M/B:A/M:M/D:T/2026-05-20T13:05:44Z/
Decision: Track
Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2026/34xxx/CVE-2026-34390.json
Source Advisory: vulnrichment/CVE-2026-34390
[{'Exploitation': 'poc'},
{'Automatable': 'yes'},
{'Technical Impact': 'partial'},
{'Mission Prevalence': 'minimal'},
{'Public Well-being Impact': 'material'},
{'Mission & Well-being': 'medium'}]