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)

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-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.(CVE-2026-71971)

U-Boot through 2026.10-rc5 contains an out-of-bounds write vulnerability in the video_display_rle8_bitmap function in drivers/video/video_bmp.c. Attackers can supply a crafted RLE8-compressed BMP image to corrupt memory adjacent to the framebuffer and crash the bootloader.(CVE-2026-71972)

U-Boot before 2026.10-rc4 contains an integer overflow vulnerability in sqfs_read_directory_table() function when allocating the directory table buffer. Attackers can supply a crafted SquashFS image with an attacker-controlled superblock metablks_count value that causes heap buffer under-allocation and out-of-bounds writes, corrupting heap memory and crashing the bootloader.(CVE-2026-71973)

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_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.

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.

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)