CVE-2026-34579Network attack vector

Private-issue disclosure via project-level monitoring check

Published May 19, 2026 · Updated May 19, 2026

Authorization bypass in MantisBT 2.26.1 through 2.28.1 allows remote authenticated users to receive private-issue updates. MonitorAddCommand validates self-monitoring against the project-level monitor threshold instead of checking access to the target issue, then records the monitor relationship. Project-level access and a crafted POST to bug_monitor_add.php expose issue metadata and content through email notifications, while direct issue access stays blocked.

CVSS severity5.3
Medium
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization bypass in MantisBT 2.26.1 through 2.28.1 allows remote authenticated users to receive private-issue updates. MonitorAddCommand validates self-monitoring against the project-level monitor threshold instead of checking access to the target issue, then records the monitor relationship. Project-level access and a crafted POST to bug_monitor_add.php expose issue metadata and content through email notifications, while direct issue access stays blocked.

The record

CVE
CVE-2026-34579
Published
May 19, 2026
Updated
May 19, 2026
Vendor
MantisBT
Product
MantisBT
Classifications
CWE-863, CWE-201, CWE-200, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 19, 2026CVE publishedPublication date reported by the CVE source.
  2. May 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 2.28.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

MantisBT · MantisBTversion=< 2.28.2

Published CVSS scores

5.3GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-863Incorrect Authorization
CWE-201Insertion of Sensitive Information Into Sent Data
CWE-200Exposure of Sensitive Information to an Unauthorized Actor
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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