CVE-2026-45915
Published May 27, 2026
Modified May 27, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: fat: avoid parent link count underflow in rmdir Corrupted FAT images can leave a directory inode with an incorrect i_nlink (e.g. 2 even though subdirectories exist). rmdir then unconditionally calls drop_nlink(dir) and can drive i_nlink to 0, triggering the WARN_ON in drop_nlink(). Add a sanity check in vfat_rmdir() and msdos_rmdir(): only drop the parent link count when it is at least 3, otherwise report a filesystem error.
References
Other References
https://git.kernel.org/stable/c/17866f8a0822d414cb02e621cf003a7d04396ef8
https://git.kernel.org/stable/c/7fe0de287e931e07cb96ecf1f449b2ebdb0e1115
https://git.kernel.org/stable/c/8cafcb881364af5ef3a8b9fed4db254054033d8a
https://git.kernel.org/stable/c/955c5d670b5ae07c78f4345e23a895638db96ce1
https://git.kernel.org/stable/c/9894c79fd9466612d0514be157b5c30cd93aa645
https://git.kernel.org/stable/c/cd569b87378b9c33ae13c23d6bb9d205d66f7c4b
https://git.kernel.org/stable/c/d0bb592fa9def2bace90ac8926c0a1d6fa8c1aa0
https://git.kernel.org/stable/c/d3b7ffa90f613938128432c7b2f35b7aa4bdd86b
Frequently Asked Questions
What is CVE-2026-45915? +
In the Linux kernel, the following vulnerability has been resolved:
fat: avoid parent link count underflow in rmdir
Corrupted FAT images can leave a directory inode with an incorrect
i_nlink (e.g. 2 even though subdirectories exist). rmdir then
unconditionally calls drop_nlink(dir) and can drive i_nlink to 0,
triggering the WARN_ON in drop_nlink().
Add a sanity check in vfat_rmdir() and msdos_rmdir(): only drop the
parent link count when it is at least 3, otherwise report a filesystem
error.
How do I check if I'm vulnerable to CVE-2026-45915? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.