Cyber Posture

CVE-2026-43939

High

Published: 12 May 2026

Published
12 May 2026
Modified
12 May 2026
KEV Added
Patch
CVSS Score 7.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
EPSS Score N/A
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-43939 is a high-severity Cross-site Scripting (CWE-79) vulnerability. Its CVSS base score is 7.3 (High).

Operationally, it is not currently listed in the CISA KEV catalog.

Threat & Defense Details

Likely Mitigating ControlsAI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-79 CWE-116

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

addresses: CWE-79

Validates web inputs to reject script-related content that could produce XSS.

NVD 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…

more

adequate HTML sanitization or contextual output encoding. This vulnerability is fixed in 4.0.5 and 3.2.12.

Deeper analysisAI

Automated synthesis unavailable for this CVE.

Details

CWE(s)

References