Administrator impersonation via unbound SOAP cookie
Published Sep 9, 2026 · Updated Sep 10, 2026
Authentication bypass in MantisBT 2.28.3 and earlier allows remote attackers to impersonate any user through the SOAP API. The mci_check_login() function validates a supplied cookie_string against any account but trusts a separately supplied username without verifying that the cookie belongs to it. Default self-registration lets attackers obtain a valid cookie with no prior access, then gain administrator-level read, write, and delete access through SOAP.
Summary
What happened
Authentication bypass in MantisBT 2.28.3 and earlier allows remote attackers to impersonate any user through the SOAP API. The mci_check_login() function validates a supplied cookie_string against any account but trusts a separately supplied username without verifying that the cookie belongs to it. Default self-registration lets attackers obtain a valid cookie with no prior access, then gain administrator-level read, write, and delete access through SOAP.
The record
- CVE
- CVE-2026-47156
- Published
- Sep 9, 2026
- Updated
- Sep 10, 2026
- Vendor
- MantisBT
- Product
- MantisBT
- Classifications
- CWE-287, CWE-639
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 9, 2026CVE publishedPublication date reported by the CVE source.
- Sep 10, 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.
- Affected versionversion=< 2.28.4
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
- MantisBT SOAP API authentication-bypass proof of conceptproof of concept · demonstrated
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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