CVE-2020-13962 · Qt 5.12.2 through 5.14.2 as used in unofficial builds of Mumble 1.3.0 and other products mishandles OpenSSL's error queue which can cause a denial of service to QSslSocket users. Because errors leak in unrelated TLS sessions an unrelated session may be disconnected when any handshake fails. (Mumble 1.3.1 is not affected regardless of the Qt version.)

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.