YetAnotherForum.NET (YAF.NET) is a C# ASP.NET forum. Prior to 4.0.5 and 3.2.12, the thread posting and reply feature accepts user-supplied content via a a post or reply that is stored server-side and later rendered back into the thread page without adequate HTML sanitization or contextual output encoding. This vulnerability is fixed in 4.0.5 and 3.2.12.
History

Tue, 12 May 2026 15:00:00 +0000

Type Values Removed Values Added
Description YetAnotherForum.NET (YAF.NET) is a C# ASP.NET forum. Prior to 4.0.5 and 3.2.12, the thread posting and reply feature accepts user-supplied content via a a post or reply that is stored server-side and later rendered back into the thread page without adequate HTML sanitization or contextual output encoding. This vulnerability is fixed in 4.0.5 and 3.2.12.
Title YAF.NET: Stored XSS in Forum Thread Posts/Replies Allowing Arbitrary JavaScript Execution for All Thread Viewers
Weaknesses CWE-116
CWE-79
CWE-80
References
Metrics cvssV3_1

{'score': 7.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-12T13:56:39.586Z

Reserved: 2026-05-04T16:59:09.089Z

Link: CVE-2026-43939

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-05-12T15:16:15.647

Modified: 2026-05-12T15:16:15.647

Link: CVE-2026-43939

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-12T16:30:19Z