Vulnerability · Published Apr 22, 2026 · Assigned by canonical

CVE-2026-35346uutils coreutils comm Silent Data Corruption via Lossy UTF-8 Normalization

Low 3.3

In plain English

A low-severity security flaw in coreutils from Uutils. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 7% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)3.3Low

Exploit odds (30 days)0.2%top 92.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	rust-coreutils	no fix listed	DEBIAN-CVE-2026-35346
Debian:13	rust-coreutils	no fix listed	DEBIAN-CVE-2026-35346
Debian:14	rust-coreutils	0.6.0-1	DEBIAN-CVE-2026-35346
Ubuntu:24.04:LTS	rust-coreutils	no fix listed	UBUNTU-CVE-2026-35346
Ubuntu:25.10	rust-coreutils	no fix listed	UBUNTU-CVE-2026-35346

Affected products (as reported)

Vendor	Product	Versions
Uutils	coreutils	0 – before 0.6.0

Weakness: CWE-176 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

References

https://github.com/uutils/coreutils/pull/10206 patch
https://github.com/uutils/coreutils/issues/10192 issue-tracking
https://github.com/uutils/coreutils/releases/tag/0.6.0 vendor-advisory