What’s Vulnerable › Vulnerabilities

CVE-2026-71973: U-Boot before 2026.10-rc4 Integer Overflow in SquashFS Directory Table Allocation

• Severity: medium (CVSS 5.2 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-29 · updated 2026-10-02
• Weakness: CWE-190

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.

Affected products

• u-boot: before 2026.10-rc4 — fixed in 2026.10-rc4

How to fix

Upgrade to a fixed version: u-boot 2026.10-rc4. Check the vendor advisory for mitigations.

References

• https://github.com/u-boot/u-boot
• https://github.com/u-boot/u-boot/blob/v2026.07/fs/squashfs/sqfs.c#L814
• https://github.com/u-boot/u-boot/commit/561ae28cb56a082cfa90c1c421c4955bc215470b
• https://www.vulncheck.com/advisories/u-boot-before-2026.10-rc4-integer-overflow-in-squashfs-directory-table-allocation

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