CVE-2026-74220

This package includes the mkimage program, which allows generation of U-Boot images in various formats, and the fw_printenv and fw_setenv programs to read and modify U-Boot's environment.

Security Fix(es):

U-Boot before 2026.10-rc5 contains a buffer overflow in nfs_read_reply() function in net/nfs-common.c that allows attackers to corrupt memory by supplying crafted NFS READ reply lengths. A malicious NFS server can exploit signed integer handling to bypass length validation and write far past the destination buffer, crashing the bootloader or corrupting memory.(CVE-2026-74220)

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.(CVE-2026-74221)

This package includes the mkimage program, which allows generation of U-Boot images in various formats, and the fw_printenv and fw_setenv programs to read and modify U-Boot's environment.

Security Fix(es):

U-Boot before 2026.10-rc5 contains a buffer overflow in nfs_read_reply() function in net/nfs-common.c that allows attackers to corrupt memory by supplying crafted NFS READ reply lengths. A malicious NFS server can exploit signed integer handling to bypass length validation and write far past the destination buffer, crashing the bootloader or corrupting memory.(CVE-2026-74220)

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.(CVE-2026-74221)

This package includes the mkimage program, which allows generation of U-Boot images in various formats, and the fw_printenv and fw_setenv programs to read and modify U-Boot's environment.

Security Fix(es):

U-Boot before 2026.10-rc5 contains a buffer overflow in nfs_read_reply() function in net/nfs-common.c that allows attackers to corrupt memory by supplying crafted NFS READ reply lengths. A malicious NFS server can exploit signed integer handling to bypass length validation and write far past the destination buffer, crashing the bootloader or corrupting memory.(CVE-2026-74220)

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.(CVE-2026-74221)

U-Boot before 2026.10-rc5 contains a buffer overflow in nfs_read_reply() function in net/nfs-common.c that allows attackers to corrupt memory by supplying crafted NFS READ reply lengths. A malicious NFS server can exploit signed integer handling to bypass length validation and write far past the destination buffer, crashing the bootloader or corrupting memory.

U-Boot before 2026.10-rc5 contains a buffer overflow in nfs_read_reply() function in net/nfs-common.c that allows attackers to corrupt memory by supplying crafted NFS READ reply lengths. A malicious NFS server can exploit signed integer handling to bypass length validation and write far past the destination buffer, crashing the bootloader or corrupting memory.

Shahriyar Jalayeri and Mehrun P. Hunter discovered that U-Boot incorrectly handled certain NFS READ and NFS READLINK responses. An attacker could possibly use this issue to trigger a buffer overflow, resulting in a denial of service or arbitrary code execution. (CVE-2026-74220, CVE-2026-74221)

Shahriyar Jalayeri and Mehrun P. Hunter discovered that U-Boot incorrectly handled certain HTTP data storage failures in its lwIP implementation. An attacker could possibly use this issue to trigger a use-after-free, resulting in a denial of service. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-74222)

Shahriyar Jalayeri and Mehrun P. Hunter discovered that U-Boot did not properly validate certain DHCPv6 option lengths during network boot. An attacker could possibly use this issue to trigger out-of-bounds memory access, resulting in a denial of service. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-74225)

USN-8930-1 fixed some vulnerabilities in U-Boot. This update provides the corresponding fix for U-Boot on Ubuntu 26.10.

Original advisory details:

Shahriyar Jalayeri and Mehrun P. Hunter discovered that U-Boot incorrectly handled certain NFS READ and NFS READLINK responses. An attacker could possibly use this issue to trigger a buffer overflow, resulting in a denial of service or arbitrary code execution. (CVE-2026-74220, CVE-2026-74221)

Shahriyar Jalayeri and Mehrun P. Hunter discovered that U-Boot incorrectly handled certain HTTP data storage failures in its lwIP implementation. An attacker could possibly use this issue to trigger a use-after-free, resulting in a denial of service. (CVE-2026-74222)

Shahriyar Jalayeri and Mehrun P. Hunter discovered that U-Boot did not properly validate certain DHCPv6 option lengths during network boot. An attacker could possibly use this issue to trigger out-of-bounds memory access, resulting in a denial of service. (CVE-2026-74225)