Vulnerability in u-boot

[ Description ]Official description

U-Boot before 2026.10-rc5 contains out-of-bounds memory access in dhcp6_parse_options() that fails to validate SERVERID and CLIENTID option lengths from DHCPv6 packets. Attackers on the local network can send crafted DHCPv6 ADVERTISE or REPLY packets during netboot to corrupt 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/dhcpv6.c
• github.com/u-boot/u-boot/commit/20209a62bc8565fc1e040882bc03c71ff0d73076
• www.vulncheck.com/advisories/u-boot-before-2026.10-rc5-out-of-bounds-write-via-dhcpv6