undici vulnerable to cookie attribute injection via unsanitized domain and unparsed setCookie fields
CVE-2026-16729
Summary
Deserialization of untrusted data in .NET allows an unauthorized attacker to execute code over a network.
Products covered
.NET 11.0 installed on Windows
.NET 10.0 installed on Windows
.NET 8.0 installed on Windows
.NET 9.0 installed on Windows
Microsoft Visual Studio 2022 version 17.14
Microsoft Visual Studio 2026 version 18.10
Remediation
Release Notes Install KB5130036. Install KB5130034. Install KB5130035.
Vendor-listed fixes
11.0.0-rc.2
10.0.13
8.0.32
9.0.21
17.14.42
18.10.4
CVEs in this advisory 1
Update history
What changed in later vendor updates
SecurityAlert records field-level changes from the point we begin following a bulletin. Earlier vendor changes may not have a field-by-field record.
- The vendor changed its remediation guidance.
Updates
- Published by Microsoft Security Response Center
The publication date reported by the vendor.
- Added to SecurityAlert
We collected the advisory from the official source.
- Updated by Microsoft Security Response Center
The vendor changed the advisory after it was first published.
- Confirmed at the source
Our collector saw this advisory during a later source check.