myBB Forums 1.8.26 contains a stored cross-site scripting vulnerability in the template management system that allows authenticated administrators to inject malicious scripts when creating new templates. Attackers can exploit this vulnerability by inserting script payloads in the template title field when adding new templates through the 'Templates and Style' > 'Templates' > 'Manage Templates' > 'Global Templates' interface, causing arbitrary JavaScript to execute when the template is viewed.

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Attack Requirements None

User Interaction Passive

Vulnerable System Confidentiality Impact Low

Vulnerable System Integrity Impact Low

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact Low

Subsequent System Integrity Impact Low

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Changed

Confidentiality Impact Low

Integrity Impact Low

Availability Impact None

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation none

Automatable no

Technical Impact partial

Affected Vendors & Products

Vendors Products
Mybb
  • Mybb

Configuration 1 [-]

cpe:2.3:a:mybb:mybb:1.8.26:*:*:*:*:*:*:*

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References
Link Providers
https://mybb.com/ cve-icon cve-icon
https://www.cve.org/CVERecord?id=CVE-2021-41866 cve-icon
https://www.exploit-db.com/exploits/51136 cve-icon cve-icon
https://www.vulncheck.com/advisories/mybb-forums-stored-cross-site-scripting-via-template-management cve-icon cve-icon
History

Sat, 27 Dec 2025 19:30:00 +0000

Type Values Removed Values Added
References

Sat, 27 Dec 2025 17:00:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 6.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N'}

 cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N'}

Fri, 26 Dec 2025 16:15:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:mybb:mybb:1.8.26:*:*:*:*:*:*:*

Tue, 23 Dec 2025 23:00:00 +0000

Type Values Removed Values Added
First Time appeared Mybb
Mybb mybb
Vendors & Products Mybb
Mybb mybb

Mon, 22 Dec 2025 23:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Mon, 22 Dec 2025 21:45:00 +0000

Type Values Removed Values Added
Description myBB Forums 1.8.26 contains a stored cross-site scripting vulnerability in the template management system that allows authenticated administrators to inject malicious scripts when creating new templates. Attackers can exploit this vulnerability by inserting script payloads in the template title field when adding new templates through the 'Templates and Style' > 'Templates' > 'Manage Templates' > 'Global Templates' interface, causing arbitrary JavaScript to execute when the template is viewed.
Title myBB Forums 1.8.26 Stored Cross-Site Scripting via Template Management
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 6.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N'}

cvssV4_0

{'score': 5.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N'}
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published: 2025-12-22T21:35:34.716Z

Updated: 2025-12-27T19:03:58.664Z

Reserved: 2025-12-20T16:31:20.899Z

Link: CVE-2023-53976

cve-icon Vulnrichment

Updated: 2025-12-27T19:03:58.664Z

cve-icon NVD

Status : Modified

Published: 2025-12-22T22:16:03.020

Modified: 2025-12-27T19:15:39.940

Link: CVE-2023-53976

cve-icon Redhat

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