Evidence used
- No CISA KEV confirmation is currently recorded.
- A structured source references public exploit or proof-of-concept material.
- EPSS is 0.47% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-34390High confidence
MantisBT: Privilege Escalation from Manager to Administrator
mantisbt · mantisbt
Official source article: GitHub GHSA-FRF7-JHP9-JXM6 ↗. Check the applicable product and release in the original source.
5.1MediumCVSS 4.0
Within 7 days
Patch availableMedium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:High, raised one band.upgradedsince 20 May 2026
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Increase monitoring for the attack path and post-exploitation behaviour described in the report.
Verification
- Confirm that the asset runs mantisbt mantisbt and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Open-source package ranges2 source-attributed ranges
These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.
| Ecosystem and package | Affected range | First fixed version | Evidence |
|---|---|---|---|
| Packagistmantisbt/mantisbt | ECOSYSTEM: introduced 0; fixed 2.28.2 | 2.28.2 | OSV record ↗aggregator derived · 10 Sep 2026 |
| composermantisbt/mantisbt | <= 2.28.1 | 2.28.2 | GitHub advisory ↗upstream repository advisory · 5 Jun 2026 |
Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
Patch available01
What, why and how
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.
What
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.
Why
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
How
An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may gain additional privileges.
What
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.
Why
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
How
An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may gain additional privileges.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material Reference recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.CISA Vulnrichment records proof-of-concept exploitation in its SSVC data. BlackTree has not independently executed or validated exploit material.
- Likely attack path
- a network path → Improper Access Control → gain additional privileges
- Attack surface
- Network
- Privileges required
- High: elevated access is required
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Not a CVSS 4.0 base metric
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-284 ↗
CWE-284: Improper Access Control. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:NCommon Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATNoneAttack requirements: No additional deployment or execution condition is required.PRHighPrivileges required: The attacker needs elevated or administrative privileges.UINoneUser interaction: No action by another user is required.VCLowVulnerable-system confidentiality: A successful attack can cause a limited loss.VILowVulnerable-system integrity: A successful attack can cause a limited loss.VANoneVulnerable-system availability: No direct loss is represented by this metric.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.- Post-exploitation / living off the land
- No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Patch available
- Affected
- mantisbt: < 2.28.2
- Fixed
- 2.28.2.
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 19 May 2026 · Last source change 20 May 2026, 13:05 UTC · CWE-284 · Improper Access Control
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-30994
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD not scheduled
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
CVE published
Fixed release or patch reference recorded
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.