U-Boot up to 2026.10-rc3 SquashFS Image sqfs_read_directory_table metablks_count integer overflow

Summaryinfo

A vulnerability was found in U-Boot up to 2026.10-rc3. It has been declared as critical. The affected element is the function sqfs_read_directory_table of the component SquashFS Image Handler. Executing a manipulation of the argument metablks_count can lead to integer overflow. This vulnerability is tracked as CVE-2026-71973. The attack can be launched remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in U-Boot up to 2026.10-rc3. It has been declared as critical. This vulnerability affects the function sqfs_read_directory_table of the component SquashFS Image Handler. The manipulation of the argument metablks_count with an unknown input leads to a integer overflow vulnerability. The CWE definition for the vulnerability is CWE-190. The product performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control. As an impact it is known to affect integrity, and availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability was named CVE-2026-71973 since 08/08/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are known, but there is no available exploit.

Upgrading to version 2026.10-rc4 eliminates this vulnerability.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Name

• U-Boot

Version

• 2026.10-rc1
• 2026.10-rc2
• 2026.10-rc3

Website

• Product: https://github.com/u-boot/u-boot/

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