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. --- _Zellic finding 3.34. Reported in the Zellic *uutils coreutils Program Security Assessment* (for Canonical, Jan 2026), audited commit `3a07ffc5a9bd4c283e75afa548ba1f1957bad242`._
Update uu_comm to 0.6.0 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scancomm: lossy UTF-8 conversion silently corrupts non-UTF-8 output affects uu_comm (rust). Severity is low. 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. --- _Zellic finding 3.34. Reported in the Zellic *uutils coreutils Program Security Assessment* (for Canonical, Jan 2026), audited commit `3a07ffc5a9bd4c283e75afa548ba1f1957bad242`._
AI coding agents often install or upgrade packages automatically in rust. A low vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|---|---|
| uu_commrust |
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. --- _Zellic finding 3.34. Reported in the Zellic *uutils coreutils Program Security Assessment* (for Canonical, Jan 2026), audited commit `3a07ffc5a9bd4c283e75afa548ba1f1957bad242`._
Update uu_comm to 0.6.0 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scancomm: lossy UTF-8 conversion silently corrupts non-UTF-8 output affects uu_comm (rust). Severity is low. 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. --- _Zellic finding 3.34. Reported in the Zellic *uutils coreutils Program Security Assessment* (for Canonical, Jan 2026), audited commit `3a07ffc5a9bd4c283e75afa548ba1f1957bad242`._
AI coding agents often install or upgrade packages automatically in rust. A low vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|---|---|
| uu_commrust |
| <0.6.0 |
| 0.6.0 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL Guard| <0.6.0 |
| 0.6.0 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL Guard