CVE-2026-72188 ntfs: sanitize MFT references returned from ntfs_lookup_inode_by_name()
A crafted NTFS image can cause the Linux kernel to consume invalid error codes, potentially leading to system instability or denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-72188?
CVE-2026-72188 is a critical vulnerability in Linux, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ntfs: sanitize MFT references returned from ntfs_lookup_inode_by_name()
ntfs_lookup_inode_by_name() returns MFT references read from directory index entries on disk. These values are untrusted, but the function can currently return an error-marked MFT reference to its callers without validating it.
Callers later decode lookup failures with MREF_ERR(). A crafted NTFS image can set the MREF error bit while leaving the low bits as an arbitrary value, causing callers to consume a bogus pseudo-errno instead of treating the lookup result as corrupted on-disk metadata.
Fix this at the source by normalizing every error-marked MFT reference returned from ntfs_lookup_inode_by_name() to ERR_MREF(-EIO). Apply this to all four directory lookup return paths so every caller gets a validated result without needing additional checks or an API change.
This keeps the sanitization in the common lookup helper, which is cleaner than duplicating validation in each caller.
Which versions are affected by CVE-2026-72188?
How do I fix CVE-2026-72188?
Apply the vendor's patch.
Is CVE-2026-72188 being exploited?
There is no known exploitation of CVE-2026-72188 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-72188, GHSA-mp9c-j9qx-8x7c, UBUNTU-CVE-2026-72188.