squashfs_opendir in unsquash-2.c in Squashfs-Tools 4.5 allows Directory Traversal a different vulnerability than CVE-2021-40153. A squashfs filesystem that has been crafted to include a symbolic link and then contents under the same filename in a filesystem can cause unsquashfs to first create the symbolic link pointing outside the expected directory and then the subsequent write operation will cause the unsquashfs process to write through the symbolic link elsewhere in the filesystem.

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.