RHSA-2026:21294 — Security Advisory
Red Hat Security Advisory: .NET 9.0 security update
Severity
ImportantRed Hat Product Security
Products
Official CSAF product identity
Published · May 27, 2026
Updated · June 30, 2026
Topic
An update for .NET 9.0 is now available for Red Hat Enterprise Linux 8.
Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.
Description
.NET is a managed-software framework. It implements a subset of the .NET framework APIs and several new APIs, and it includes a CLR implementation.
New versions of .NET that address a security vulnerability are now available. The updated versions are .NET SDK 9.0.117 and .NET Runtime 9.0.16.Security Fix(es):
- dotnet: .NET: infinite loop allows an attacker to cause a denial of service (CVE-2026-42899)
For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.