CVE-2026-71973
U-Boot before 2026.10-rc4 Integer Overflow in SquashFS Directory Table Allocation
u-boot u-boot
CVSS
5.2MediumExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.18%Chance of exploitation activity in the next 30 days, higher than 7% of CVEs. Scored 23 Oct 2026FIRST EPSS
What fixes it
- 2026.10-rc4u-bootCVE List
A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.
Description
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.
Text from CVE List
Affected versions 1
- u-bootaffected: all versions before 2026.10-rc4CVE List
References 4
- github.com/u-boot/u-boot/commit/561ae28cb56a082cfa90c1c421c4955bc215470bFixvia CVE List
- vulncheck.com/advisories/u-boot-before-2026.10-rc4-integer-overflow-in-squashfs-directory-table-allocationAdvisoryvia CVE List
- github.com/u-boot/u-boot/blob/v2026.07/fs/squashfs/sqfs.c#L814Referencevia CVE List
- github.com/u-boot/u-bootReferencevia CVE List