The comm utility in uutils coreutils silently corrupts data by performing lossy UTF-8 conversion on all output lines. The implementation uses String::from_utf8_lossy(), which replaces invalid UTF-8 byte sequences with the Unicode replacement character (U+FFFD). This behavior differs from GNU comm, which processes raw bytes and preserves the original input. This results in corrupted output when the utility is used to compare binary files or files using non-UTF-8 legacy encodings.

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Wed, 22 Apr 2026 16:30:00 +0000

Type Values Removed Values Added
Description The comm utility in uutils coreutils silently corrupts data by performing lossy UTF-8 conversion on all output lines. The implementation uses String::from_utf8_lossy(), which replaces invalid UTF-8 byte sequences with the Unicode replacement character (U+FFFD). This behavior differs from GNU comm, which processes raw bytes and preserves the original input. This results in corrupted output when the utility is used to compare binary files or files using non-UTF-8 legacy encodings.
Title uutils coreutils comm Silent Data Corruption via Lossy UTF-8 Normalization
Weaknesses CWE-176
References
Metrics cvssV3_1

{'score': 3.3, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: canonical

Published:

Updated: 2026-04-22T16:07:51.755Z

Reserved: 2026-04-02T12:58:56.087Z

Link: CVE-2026-35346

cve-icon Vulnrichment

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cve-icon NVD

Status : Received

Published: 2026-04-22T17:16:36.760

Modified: 2026-04-22T17:16:36.760

Link: CVE-2026-35346

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses