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6 vulnerabilities found for YAFNET by YAFNET

CVE-2026-43939 (GCVE-0-2026-43939)

Vulnerability from nvd – Published: 2026-05-12 13:56 – Updated: 2026-05-13 14:38
VLAI
Title
YAF.NET: Stored XSS in Forum Thread Posts/Replies Allowing Arbitrary JavaScript Execution for All Thread Viewers
Summary
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.
Severity
7.3 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
CWE
  • CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
  • CWE-80 - Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
  • CWE-116 - Improper Encoding or Escaping of Output
Assigner
References
Impacted products
Vendor Product Version
YAFNET YAFNET Affected: >= 4.0.0-beta.1, < 4.0.5
Affected: < 3.2.12
Create a notification for this product.
Show details on NVD website
To clipboard 

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CVE-2026-43938 (GCVE-0-2026-43938)

Vulnerability from nvd – Published: 2026-05-12 13:57 – Updated: 2026-05-12 15:39
VLAI
Title
YAF.NET: Unauthenticated Stored Second-Order XSS in Admin Event Log via Reflected `User-Agent` Header
Summary
YetAnotherForum.NET (YAF.NET) is a C# ASP.NET forum. Prior to 4.0.5 and 3.2.12, the application's database logger (YAFNET.Core/Logger/DbLogger.cs) captures the incoming request's User-Agent header into a JObject, serializes it with JsonConvert, and stores the result in the EventLog.Description column whenever an event (e.g., an unhandled exception) is logged. The admin event-log page (YetAnotherForum.NET/Pages/Admin/EventLog.cshtml.cs) later deserializes that JSON in FormatStackTrace() and interpolates the UserAgent value directly into an HTML string with no encoding, and the Razor view EventLog.cshtml emits the result through @Html.Raw. This vulnerability is fixed in 4.0.5 and 3.2.12.
Severity
8.1 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
CWE
  • CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
  • CWE-80 - Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
  • CWE-116 - Improper Encoding or Escaping of Output
Assigner
References
Impacted products
Vendor Product Version
YAFNET YAFNET Affected: >= 4.0.0-beta.1, < 4.0.5
Affected: < 3.2.12
Create a notification for this product.
Show details on NVD website
To clipboard 

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CVE-2026-43937 (GCVE-0-2026-43937)

Vulnerability from nvd – Published: 2026-05-12 14:00 – Updated: 2026-05-12 15:42
VLAI
Title
YAF.NET: Pre-Handler Authorization Bypass on Admin Pages Enabling Blind SQL Execution via `/Admin/RunSql`
Summary
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.
Severity
8.8 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
  • CWE-89 - Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
  • CWE-841 - Improper Enforcement of Behavioral Workflow
Assigner
References
Impacted products
Vendor Product Version
YAFNET YAFNET Affected: < 4.0.5
Create a notification for this product.
Show details on NVD website
To clipboard 

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CVE-2026-43937 (GCVE-0-2026-43937)

Vulnerability from cvelistv5 – Published: 2026-05-12 14:00 – Updated: 2026-05-12 15:42
VLAI
Title
YAF.NET: Pre-Handler Authorization Bypass on Admin Pages Enabling Blind SQL Execution via `/Admin/RunSql`
Summary
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.
Severity
8.8 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
  • CWE-89 - Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
  • CWE-841 - Improper Enforcement of Behavioral Workflow
Assigner
References
Impacted products
Vendor Product Version
YAFNET YAFNET Affected: < 4.0.5
Create a notification for this product.
Show details on NVD website
To clipboard 

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CVE-2026-43938 (GCVE-0-2026-43938)

Vulnerability from cvelistv5 – Published: 2026-05-12 13:57 – Updated: 2026-05-12 15:39
VLAI
Title
YAF.NET: Unauthenticated Stored Second-Order XSS in Admin Event Log via Reflected `User-Agent` Header
Summary
YetAnotherForum.NET (YAF.NET) is a C# ASP.NET forum. Prior to 4.0.5 and 3.2.12, the application's database logger (YAFNET.Core/Logger/DbLogger.cs) captures the incoming request's User-Agent header into a JObject, serializes it with JsonConvert, and stores the result in the EventLog.Description column whenever an event (e.g., an unhandled exception) is logged. The admin event-log page (YetAnotherForum.NET/Pages/Admin/EventLog.cshtml.cs) later deserializes that JSON in FormatStackTrace() and interpolates the UserAgent value directly into an HTML string with no encoding, and the Razor view EventLog.cshtml emits the result through @Html.Raw. This vulnerability is fixed in 4.0.5 and 3.2.12.
Severity
8.1 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
CWE
  • CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
  • CWE-80 - Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
  • CWE-116 - Improper Encoding or Escaping of Output
Assigner
References
Impacted products
Vendor Product Version
YAFNET YAFNET Affected: >= 4.0.0-beta.1, < 4.0.5
Affected: < 3.2.12
Create a notification for this product.
Show details on NVD website
To clipboard 

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CVE-2026-43939 (GCVE-0-2026-43939)

Vulnerability from cvelistv5 – Published: 2026-05-12 13:56 – Updated: 2026-05-13 14:38
VLAI
Title
YAF.NET: Stored XSS in Forum Thread Posts/Replies Allowing Arbitrary JavaScript Execution for All Thread Viewers
Summary
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.
Severity
7.3 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
CWE
  • CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
  • CWE-80 - Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
  • CWE-116 - Improper Encoding or Escaping of Output
Assigner
References
Impacted products
Vendor Product Version
YAFNET YAFNET Affected: >= 4.0.0-beta.1, < 4.0.5
Affected: < 3.2.12
Create a notification for this product.
Show details on NVD website
To clipboard 

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