An issue was discovered in RDoc 6.3.3 through 6.6.2 as distributed in Ruby 3.x through 3.3.0. When parsing .rdoc_options (used for configuration in RDoc) as a YAML file object injection and resultant remote code execution are possible because there are no restrictions on the classes that can be restored. (When loading the documentation cache object injection and resultant remote code execution are also possible if there were a crafted cache.) The main fixed version is 6.6.3.1. For Ruby 3.0 users a fixed version is rdoc 6.3.4.1. For Ruby 3.1 users a fixed version is rdoc 6.4.1.1. For Ruby 3.2 users a fixed version is rdoc 6.5.1.1.

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.