Vulnerability in u-boot

[ Description ]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.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund29 Sep 2026WID-SEC-2026-3660

  DENX U-Boot: Multiple vulnerabilities Translated from German

  Risk highCVE-2026-74221CVE-2026-74222CVE-2026-74220+5 more CVEs

[ References ]References

• github.com/u-boot/u-boot
• github.com/u-boot/u-boot/blob/v2026.07/net/net.c
• github.com/u-boot/u-boot/commit/04ca915d5bf39dda5d1bce62d04d2b59d293c5b9
• www.vulncheck.com/advisories/u-boot-before-2026.10-rc3-out-of-bounds-write-in-ip-fragme…