undici vulnerable to cookie attribute injection via unsanitized domain and unparsed setCookie fields
CVE-2026-16729
Summary
Inconsistent interpretation of http requests ('http request/response smuggling') in ASP.NET Core allows an unauthorized attacker to bypass a security feature over a network.
Products covered
Microsoft Visual Studio 2026 version 18.10
Microsoft Visual Studio 2022 version 17.14
ASP.NET Core 11.0
ASP.NET Core 9.0
ASP.NET Core 10.0
ASP.NET Core 8.0
Remediation
Release Notes Install KB5130035. Install KB5130036. Install KB5130034.
Vendor-listed fixes
18.10.4
17.14.42
11.0.0-rc.2
9.0.21
10.0.13
8.0.32
CVEs in this advisory 1
Update history
What changed in later vendor updates
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- The vendor changed the advisory's last-updated date.
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.