What’s Vulnerable › Vulnerabilities

CVE-2026-35347: uutils coreutils comm Silent Data Loss or Denial of Service via Improper Input Validation

• Severity: medium (CVSS 4.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-04-22 · updated 2026-10-26
• Weakness: CWE-20

Description

The comm utility in uutils coreutils incorrectly consumes data from non-regular file inputs before performing comparison operations. The are_files_identical function opens and reads from both input paths to compare content without first verifying if the paths refer to regular files. If an input path is a FIFO or a pipe, this pre-read operation drains the stream, leading to silent data loss before the actual comparison logic is executed. Additionally, the utility may hang indefinitely if it attempts to pre-read from infinite streams like /dev/zero.

Affected products

• Uutils coreutils: before 0.6.0 — fixed in 0.6.0

How to fix

Upgrade to a fixed version: Uutils coreutils 0.6.0. Check the vendor advisory for mitigations.

References

• https://github.com/uutils/coreutils/pull/9545
• https://github.com/uutils/coreutils/releases/tag/0.6.0
• https://github.com/uutils/coreutils/pull/9545

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