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Fencer Intel
medium 5.1

CVE-2026-34390 json

MantisBT: Privilege Escalation from Manager to Administrator

published 5mo ago modified last mo. also EUVD-2026-30994 , GHSA-frf7-jhp9-jxm6

cvss
5.1
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 37%
public exploits
0
none known

Summary

Mantis Bug Tracker (MantisBT) is an open source issue tracker. Versions 2.28.1 and prior have a Privilege Escalation vulnerability where insufficient access control checks in ProjectUsersAddCommand (manage_proj_user_add.php) allow 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 restricts 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. The consequences of the privilege escalation are slight, as having administrator access at Project level is effectively not very different from being manager, and 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. This issue has been fixed in version 2.28.2.

Patch / fix

  • packagist mantisbt/mantisbt 2.28.2
  • mantisbt mantisbt 2.28.2

Is CVE-2026-34390 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
5mo ago

Exploit prediction

0.43% chance of exploitation in the next 30 days, higher than 37% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • mantisbt.org https://mantisbt.org/bugs/view.php?id=36995 referenced PoC, tagged "exploit" by a source, unverified
  • mantisbt.org https://mantisbt.org/bugs/view.php?id=37002 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 5.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
CNA 4.0 5.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem package affected fixed in
packagist mantisbt/mantisbt
<2.28.2
2.28.2

Affected products

  • mantisbt mantisbt

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.