CVE-2025-46556
MantisBT is Vulnerable to Denial-of-Service (DoS) attack via Excessive Note Length
Mantis Bug Tracker (MantisBT) is an open source issue tracker. Versions 2.27.1 and below allow attackers to permanently corrupt issue activity logs by submitting extremely long notes (tested with 4,788,761 characters) due to a lack of server-side validation of note length. Once such a note is added, the activity stream UI fails to render; therefore, new notes cannot be displayed, effectively breaking all future collaboration on the issue. This issue is fixed in version 2.27.2.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
MantisBT is Vulnerable to Denial-of-Service (DoS) attack via Excessive Note Length
Mantis Bug Tracker (MantisBT) is an open source issue tracker. Versions 2.27.1 and below allow attackers to permanently corrupt issue activity logs by submitting extremely long notes (tested with 4,788,761 characters) due to a lack of server-side validation of note length. Once such a note is added, the activity stream UI fails to render; therefore, new notes cannot be displayed, effectively breaking all future collaboration on the issue. This issue is fixed in version 2.27.2.
- Record
CVE-2025-46556- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
EUVDEUVD-2025-37509
Mantis Bug Tracker (MantisBT) is an open source issue tracker. Versions 2.27.1 and below allow attackers to permanently corrupt issue activity logs by submitting extremely long notes (tested with 4,788,761 characters) due to a lack of server-side validation of note length. Once such a note is added, the activity stream UI fails to render; therefore, new notes cannot be displayed, effectively breaking all future collaboration on the issue. This issue is fixed in version 2.27.2.
- Record
EUVD-2025-37509- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-r3jf-hm7q-qfw5
MantisBT Vulnerable to Denial-of-Service (DoS) via Excessive Note Length
A lack of server-side validation for note length in MantisBT allows attackers to permanently corrupt issue activity logs by submitting extremely long notes (tested with 4,788,761 characters). Once such a note is added:
Impact
- The entire activity stream becomes unviewable (UI fails to render).
- New notes cannot be displayed, effectively breaking all future collaboration on the issue.
Patches
Fixed in 2.27.2.
Workarounds
None
Credits
Thanks to Mazen Mahmoud (@TheAmazeng) for reporting the vulnerability.
- Record
GHSA-r3jf-hm7q-qfw5- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
NVD
Mantis Bug Tracker (MantisBT) is an open source issue tracker. Versions 2.27.1 and below allow attackers to permanently corrupt issue activity logs by submitting extremely long notes (tested with 4,788,761 characters) due to a lack of server-side validation of note length. Once such a note is added, the activity stream UI fails to render; therefore, new notes cannot be displayed, effectively breaking all future collaboration on the issue. This issue is fixed in version 2.27.2.
- Record
CVE-2025-46556- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
OSV
MantisBT is Vulnerable to Denial-of-Service (DoS) attack via Excessive Note Length
Mantis Bug Tracker (MantisBT) is an open source issue tracker. Versions 2.27.1 and below allow attackers to permanently corrupt issue activity logs by submitting extremely long notes (tested with 4,788,761 characters) due to a lack of server-side validation of note length. Once such a note is added, the activity stream UI fails to render; therefore, new notes cannot be displayed, effectively breaking all future collaboration on the issue. This issue is fixed in version 2.27.2.
- Record
CVE-2025-46556- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
OSVGHSA-r3jf-hm7q-qfw5
MantisBT Vulnerable to Denial-of-Service (DoS) via Excessive Note Length
A lack of server-side validation for note length in MantisBT allows attackers to permanently corrupt issue activity logs by submitting extremely long notes (tested with 4,788,761 characters). Once such a note is added:
Impact
- The entire activity stream becomes unviewable (UI fails to render).
- New notes cannot be displayed, effectively breaking all future collaboration on the issue.
Patches
Fixed in 2.27.2.
Workarounds
None
Credits
Thanks to Mazen Mahmoud (@TheAmazeng) for reporting the vulnerability.
- Record
GHSA-r3jf-hm7q-qfw5- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
mantisbt/mantisbtPackagist |
before 2.27.2 | 2.27.2 |
mantisbt/mantisbtPackagist |
before 2.27.2, plus listed versions 2.10.02.10.12.11.02.11.12.12.0 Show 45 moreShow less2.12.12.12.22.13.02.13.12.13.22.14.02.15.02.15.12.16.02.16.12.17.02.17.12.17.22.18.02.18.12.19.02.19.12.20.02.20.12.21.02.21.12.21.22.21.32.22.02.22.12.22.22.23.02.23.12.24.02.24.12.24.22.24.32.24.42.24.52.25.02.25.12.25.22.25.32.25.42.25.52.25.62.25.72.25.82.26.02.26.1 |
2.27.2 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-46556 is a medium vulnerability (CVSS 6.5) in Mantisbt, published November 3, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.41%, the 35th percentile. Fixed in mantisbt/mantisbt 2.27.2.
References
github.com/mantisbt/mantisbt/security/advisories/GHSA-r3jf-hm7q-qfw5
nvd.nist.gov/vuln/detail/CVE-2025-46556
Left out here: 22 versions. The JSON record has them.