CVE-2026-43937: Yafnet

High severity, CVSS 8.8. EPSS: 0.6% chance of exploitation in the next 30 days.

YetAnotherForum.NET (YAF.NET) is a C# ASP.NET forum. Prior to 4.0.5, Any admin OnPost… handler executes its side effects before the ResultFilterAttribute rewrites the response to a 302 to /Info/4. The most impactful abuse is /Admin/RunSql, whose OnPostRunQuery binds Editor from the POST body and passes it straight to IDbAccess.RunSql with no caller check, yielding arbitrary SQL execution for any low-privileged user. This vulnerability is fixed in 4.0.5.

Affected products

• Yafnet Yafnet: before 4.0.5 (fixed in 4.0.5)

Published 2026-05-12. Last modified 2026-06-17.