CVE-2026-71971 U-Boot before 2026.10-rc3 Out-of-Bounds Write in IP Fragment Reassembly
Remote attackers can crash the U-Boot bootloader via crafted IP fragments during netboot if IP defragmentation is enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-71971?
CVE-2026-71971 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-rc3 with CONFIG_IP_DEFRAG enabled contains an out-of-bounds write vulnerability in the __net_defragment() function in net/net.c. Remote attackers can send a crafted IP fragment with non-zero offset and More-Fragments flag set during netboot to corrupt adjacent memory and crash the bootloader.
Weakness: CWE-787
Which versions are affected by CVE-2026-71971?
How do I fix CVE-2026-71971?
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-2026-71971 being exploited?
There is no known exploitation of CVE-2026-71971 in the wild and no public exploit code.
Sources
Also known as AZL-105711, DEBIAN-CVE-2026-71971, GHSA-9gg4-qrm6-f795, UBUNTU-CVE-2026-71971.