CVE-2026-35346

uutils coreutils comm Silent Data Corruption via Lossy UTF-8 Normalization

Published Apr 22, 2026 CVSS 3.1 · 3.3 Low EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-hwhf-8p2f-45wr coreutils' comm utility silently corrupts data by performing lossy UTF-8 conversion on all output lines
Github GHSA Github GHSA GHSA-6gcw-w7cp-94g9 comm: lossy UTF-8 conversion silently corrupts non-UTF-8 output
History
Type Values Removed Values Added
First Time appeared Uutils
Uutils coreutils
CPEs cpe:2.3:a:uutils:coreutils:*:*:*:*:*:rust:*:*
Vendors & Products Uutils
Uutils coreutils
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
canonical
Published
Updated
Apr 22, 2026, 6:12 PM
Reserved
Apr 2, 2026, 12:58 PM
Status
Analyzed
Published
Apr 22, 2026, 5:16 PM
Modified
Oct 26, 2026, 10:10 PM