CVE-2026-34390

Description

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.

Overview

State: PUBLISHED
Assigner (CNA): GitHub_M
CVSS severity: MEDIUM
CVSS score: 5.1 / 10
CVSS vector: 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
Effective score: 5.1 / 10 MEDIUM source: CNA overview
CWE(s): CWE-284
Reserved: 2026-03-27
Published: 2026-05-19 21:54 UTC
Last updated: 2026-05-20 13:05 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/34xxx/CVE-2026-34390.json
Linked Threat: CVE-2026-34390 — CVE-2026-34390

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published: 2026-05-19 22:16:37 UTC
NVD last modified: 2026-05-20 14:06:33 UTC
EPSS score: 0.0001 (probability of exploitation in next 30 days)
EPSS percentile: 1.65% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID: EUVD-2026-30994
Assigner: GitHub_M
Published: May 19, 2026, 9:54:26 PM
Updated: May 20, 2026, 1:05:47 PM
EUVD base score (CVSS 4.0): 5.1 / 10
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
EUVD-reported EPSS: 0.0200
Vendors: mantisbt
Products: mantisbt (< 2.28.2)
Aliases: GHSA-frf7-jhp9-jxm6

ENISA description: 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.

EUVD references (4)

Affected products (1)

Vendor	Product	Versions	Platforms
mantisbt	mantisbt	`< 2.28.2` (affected)	—

Vendor references (4)

References embedded in the original CVE record by the assigning CNA.

https://github.com/mantisbt/mantisbt/security/advisories/GHSA-frf7-jhp9-jxm6 x_refsource_CONFIRM
https://github.com/mantisbt/mantisbt/commit/69e0180f180ed5acf48a8d281a73683a7bf32461 x_refsource_MISC
https://mantisbt.org/bugs/view.php?id=36995 x_refsource_MISC
https://mantisbt.org/bugs/view.php?id=37002 x_refsource_MISC

Web references (7)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

https://github.com/mantisbt/mantisbt/commit/69e0180f180ed5acf48a8d281a73683a7bf32461 tenable:github.com
https://github.com/mantisbt/mantisbt/security/advisories/GHSA-frf7-jhp9-jxm6 tenable:github.com
https://mantisbt.org/bugs/view.php?id=36995 tenable:mantisbt.org
https://mantisbt.org/bugs/view.php?id=37002 tenable:mantisbt.org
https://nvd.nist.gov/vuln/detail/CVE-2026-34390 tenable:nvd.nist.gov
https://www.cve.org/CVERecord?id=CVE-2026-34390 tenable:www.cve.org
https://www.first.org/epss/ tenable:www.first.org

NVD-tagged references (6)

Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.

https://github.com/mantisbt/mantisbt/commit/69e0180f180ed5acf48a8d281a73683a7bf32461 security-advisories@github.com
https://github.com/mantisbt/mantisbt/security/advisories/GHSA-frf7-jhp9-jxm6 security-advisories@github.com
https://mantisbt.org/bugs/view.php?id=36995 security-advisories@github.com
https://mantisbt.org/bugs/view.php?id=36995 134c704f-9b21-4f2e-91b3-4a467353bcc0
https://mantisbt.org/bugs/view.php?id=37002 security-advisories@github.com
https://mantisbt.org/bugs/view.php?id=37002 134c704f-9b21-4f2e-91b3-4a467353bcc0

Remediations (15)

Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.

Microsoft and Adobe Patch Tuesday, April 2026 Security Update Review

web:blog.qualys.com

With Qualys Policy Audit's out-of-the-box mitigation or Compensatory Controls, which reduce the risk of a vulnerability being exploited because the remediation ( fix / patch ) cannot be done immediately, these security controls are not recommended by any industry standards, such as CIS and DISA-STIG.

2026-05-23 22:16 UTC
Microsoft Patch Tuesday April 2026 - 168 Vulnerabilities Fixed ...

web:cybersecuritynews.com

Microsoft has released its April 2026 Patch Tuesday security update, addressing 168 vulnerabilities across its product portfolio including one actively exploited zero-day and one publicly disclosed flaw that organizations must prioritize immediately.

2026-05-23 22:16 UTC
Patch Tuesday, May 2026 Edition - Krebs on Security

web:krebsonsecurity.com

Microsoft expects that exploitation is more likely. May's Patch Tuesday is a welcome respite from April, which saw Microsoft fix a near-record 167 security flaws.

2026-05-23 22:16 UTC
Nvd - Cve-2026-8390

web:nvd.nist.gov

An official website of the United States government Here's how you know

2026-05-23 22:16 UTC
Oracle CPU April 2026: Delayed RUs & First Analysis

web:oradba.ch

19c 26ai cve oracle-cpu patch -management release-update security Oracle CPU April 2026 : Delayed RUs & First Analysis On April 21, 2026 , Oracle released the Critical Patch Update (CPU) for April 2026 — 481 new security fixes across the entire Oracle product stack. For Oracle Database, this means another round of mandatory patching.

2026-05-23 22:16 UTC
Security Update Guide - Microsoft

web:portal.msrc.microsoft.com

The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.

2026-05-23 22:16 UTC
Microsoft April 2026 Patch Tuesday fixes 167 flaws, 2 zero-days

web:www.bleepingcomputer.com

Today is Microsoft's April 2026 Patch Tuesday with security updates for 167 flaws, including 2 zero-day vulnerabilities.

2026-05-23 22:16 UTC
April 2026 Patch Tuesday: Updates and Analysis | CrowdStrike

web:www.crowdstrike.com

Microsoft's April 2026 Patch Tuesday addresses 164 CVEs , featuring 8 Critical vulnerabilities, one exploited zero-day, and one disclosed zero-day.

2026-05-23 22:16 UTC
Oracle Critical Patch Update Advisory - April 2026

web:www.oracle.com

This Critical Patch Update contains 481 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at April 2026 Critical Patch Update: Executive Summary and Analysis.

2026-05-23 22:16 UTC
Patch Tuesday May 2026: Security Updates & CVE Analysis

web:zecurit.com

Get the complete breakdown of Microsoft's May 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .

2026-05-23 22:16 UTC
Patch Tuesday, April 2026 Edition - Krebs on Security

web:krebsonsecurity.com

For a clickable, per- patch breakdown, check out the SANS Internet Storm Center Patch Tuesday roundup. Running into problems applying any of these updates?

2026-05-26 02:58 UTC
SecuriTricks - CVE-2026-34390 - 5.1/10

web:securitricks.com

CVE CVE-2026-34390 - Score : 5.1 - Source : security-advisories@github.com - Description : 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 ...

2026-05-26 02:58 UTC
Critical Patches Issued for Microsoft Products, April 14, 2026

web:www.cisecurity.org

<p>Multiple vulnerabilities have been discovered in Microsoft products, the most severe of which could allow for remote code execution. Successful exploitation of the most severe of these vulnerabilities could result in an attacker gaining the same privileges as the logged-on user. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or ...

2026-05-26 02:58 UTC
Microsoft Technical Security Notifications

web:www.microsoft.com

Security Update Guide Notifications Microsoft's free Security Update Guide Notifications provide links to security-related software updates and notification of re-released security updates. These notifications are sent via email throughout the month as needed.

2026-05-26 02:58 UTC
Windows 11 April 2026 Update tested: What's new, improved and fixed

web:www.windowslatest.com

Windows 11 April 2026 update adds Narrator Copilot support, faster Settings, File Explorer fixes, and key security improvements.

2026-05-26 02:58 UTC

AI Forensic Analysis

Only Available for Registered Users. Sign in to view.

Raw JSON

The full cvelistV5 record. Download as CVE-2026-34390.json.

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-34390",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-20T13:05:44.018367Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-20T13:05:47.802Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://mantisbt.org/bugs/view.php?id=36995"
          },
          {
            "tags": [
              "exploit"
            ],
            "url": "https://mantisbt.org/bugs/view.php?id=37002"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "mantisbt",
          "vendor": "mantisbt",
          "versions": [
            {
              "status": "affected",
              "version": "< 2.28.2"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 5.1,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "HIGH",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "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",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "LOW"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-284",
              "description": "CWE-284: Improper Access Control",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-19T21:54:26.043Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/mantisbt/mantisbt/security/advisories/GHSA-frf7-jhp9-jxm6",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/mantisbt/mantisbt/security/advisories/GHSA-frf7-jhp9-jxm6"
        },
        {
          "name": "https://github.com/mantisbt/mantisbt/commit/69e0180f180ed5acf48a8d281a73683a7bf32461",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/mantisbt/mantisbt/commit/69e0180f180ed5acf48a8d281a73683a7bf32461"
        },
        {
          "name": "https://mantisbt.org/bugs/view.php?id=36995",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://mantisbt.org/bugs/view.php?id=36995"
        },
        {
          "name": "https://mantisbt.org/bugs/view.php?id=37002",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://mantisbt.org/bugs/view.php?id=37002"
        }
      ],
      "source": {
        "advisory": "GHSA-frf7-jhp9-jxm6",
        "discovery": "UNKNOWN"
      },
      "title": "MantisBT: Privilege Escalation from Manager to Administrator"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-34390",
    "datePublished": "2026-05-19T21:54:26.043Z",
    "dateReserved": "2026-03-27T13:45:29.619Z",
    "dateUpdated": "2026-05-20T13:05:47.802Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}