CVE-2026-35366 uutils coreutils printenv Security Inspection Bypass via UTF-8 Enforcement

What is CVE-2026-35366?

CVE-2026-35366 is a medium-severity vulnerability in Uutils coreutils, published on 22 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

The printenv utility in uutils coreutils fails to display environment variables containing invalid UTF-8 byte sequences. While POSIX permits arbitrary bytes in environment strings, the uutils implementation silently skips these entries rather than printing the raw bytes. This vulnerability allows malicious environment variables (e.g., adversarial LD_PRELOAD values) to evade inspection by administrators or security auditing tools, potentially allowing library injection or other environment-based attacks to go undetected.

Weakness: CWE-754

Which versions are affected by CVE-2026-35366?

2 open source packages ship an affected version, including uu_printenv. It affects 1 product.

Products include Uutils Coreutils.

How do I fix CVE-2026-35366?

Upgrade uu_printenv to 0.6.0 or later.

Is CVE-2026-35366 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-35366 exists.

Other vulnerabilities in Uutils coreutils

• CVE-2026-35338 uutils coreutils chmod Path Traversal Bypass of --preserve-root High 7.3
• CVE-2026-35368 uutils coreutils chroot Local Privilege Escalation and chroot Escape in via Name Service Switch (NSS) Injection High 7.2
• CVE-2026-35341 uutils coreutils mkfifo Unauthorized Permission Change on Existing Files High 7.1
• CVE-2026-35352 uutils coreutils mkfifo Privilege Escalation via TOCTOU Race Condition High 7.0
• CVE-2026-35349 uutils coreutils Path-Based Safety Bypass with --preserve-root Medium 6.7

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2026-35366, GHSA-p7h3-7q52-72w8, UBUNTU-CVE-2026-35366.