CVE-2026-46078 erofs: fix the out-of-bounds nameoff handling for trailing dirents
A crafted EROFS filesystem can trigger an integer underflow leading to out-of-bounds reads, potentially causing denial of service or information disclosure.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-46078?
CVE-2026-46078 is a high-severity vulnerability in Linux kernel, published on 27 May 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
In the Linux kernel, the following vulnerability has been resolved:
erofs: fix the out-of-bounds nameoff handling for trailing dirents
Currently we already have boundary-checks for nameoffs, but the trailing dirents are special since the namelens are calculated with strnlen() with unchecked nameoffs.
If a crafted EROFS has a trailing dirent with nameoff >= maxsize, maxsize - nameoff can underflow, causing strnlen() to read past the directory block.
nameoff0 should also be verified to be a multiple of `sizeof(struct erofs_dirent)` as well [1].
[1] https://sashiko.dev/#/patchset/20260416063511.3173774-1-hsiangkao%40linux.alibaba.com
Weakness: CWE-125
Which versions are affected by CVE-2026-46078?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-46078?
Apply the vendor's patch.
Is CVE-2026-46078 being exploited?
There is no known exploitation of CVE-2026-46078 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-88632, BELL-CVE-2026-46078, DEBIAN-CVE-2026-46078, GHSA-4rmv-8gm3-jwx2, ROOT-OS-DEBIAN-11-CVE-2026-46078, ROOT-OS-DEBIAN-12-CVE-2026-46078 and 3 more.