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Fencer Vulns
medium 4.4

CVE-2026-35366 json

uutils coreutils printenv Security Inspection Bypass via UTF-8 Enforcement

published 2026-04-22 6 mo ago modified 2026-10-26 13 d ago also GHSA-p7h3-7q52-72w8 , EUVD-2026-25014

cvss
4.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 6%
public exploits
0
none known

Summary

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.

Patch / fix

  • crates.io uu_printenv 0.6.0
  • Uutils coreutils 0.6.0
  • rust-coreutils Debian 14 0.6.0-1

debian advisories DEBIAN-CVE-2026-35366

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-35366 updated cvss 4.4

rust-coreutils: uutils coreutils printenv: Security Inspection Bypass via invalid UTF-8 environment variables

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
6 mo ago

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/uutils/coreutils/issues/9701 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 4.4 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
GitHub 3.1 4.4 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
crates.io uu_printenv
<0.6.0
0.6.0

Affected products

  • Uutils coreutils

Classification

Weakness
  • CWE-754 Improper Check for Unusual or Exceptional Conditions
  • CWE-116 Improper Encoding or Escaping of Output

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.