CVE-2026-74221 U-Boot before 2026.10-rc5 Buffer Overflow via NFS READLINK
A malicious NFS server can crash the U-Boot bootloader via a buffer overflow in the READLINK reply handler.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-74221?
CVE-2026-74221 is a high-severity memory corruption vulnerability in u-boot, published on 29 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
U-Boot before 2026.10-rc5 contains a buffer overflow in nfs_readlink_reply() function in net/nfs-common.c when processing NFS server responses. A malicious NFS server can send crafted READLINK replies with negative or oversized symlink length values to corrupt memory and crash the bootloader.
Weakness: CWE-195
Which versions are affected by CVE-2026-74221?
How do I fix CVE-2026-74221?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-74221 being exploited?
There is no known exploitation of CVE-2026-74221 in the wild and no public exploit code.
Sources
Also known as AZL-105702, DEBIAN-CVE-2026-74221, GHSA-r9ch-9wx4-f978, UBUNTU-CVE-2026-74221.