CVE-2026-35346
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._
⚡ Watch CVE-2026-35346
Get an email if CVE-2026-35346 is added to CISA KEV, gains public exploit code, or a new advisory cites it — max one per day, one-click unsubscribe.
Exploitation outlook
- Low exploitation risk0.18% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 7% of all EPSS-scored CVEs.
Advisory coverage (1)
External references
Embed the live status
— this badge updates automatically when the KEV or exploit status changes. How to embed it →
[](https://www.csirts.com/cve/CVE-2026-35346)