The team has identified a critical vulnerability in the http server of the most recent version of Node where malformed headers can lead to HTTP request smuggling. Specifically if a space is placed before a content-length header it is not interpreted correctly enabling attackers to smuggle in a second request within the body of the first.

Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability? One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional products is identified, we will update the CVE to reflect this.