CVE-2026-43939GHSA-8RQ5-WWPP-FMJ2
YAF.NET: Stored XSS in Forum Thread Posts/Replies Allowing Arbitrary JavaScript Execution for All Thread Viewers
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 4.0.5, 3.2.12
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
CISA's decision points: whether it is exploited, whether attacks can be automated, and how much control an attacker gets. Assessed (SSVC 2.0.3).What do these mean? →
- Exploitation: poc
- Automatable: no
- Technical impact: total
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.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: poc · Automatable: no · Technical impact: total
- Record last updated
Affected versions
- YAFNET YAFNET
From 4.0.0-beta.1 · fixed in 4.0.5; fixed in 3.2.12
- YAFNET.CoreNuGet
From 4.0.0-beta01 · fixed in 4.0.5
- YAFNET.CoreNuGet
fixed in 3.2.12