CVE-2026-35366
uutils coreutils printenv Security Inspection Bypass via UTF-8 Enforcement
CVE-2026-35366 is a medium vulnerability (CVSS 4.4) in Uutils Coreutils, published April 22, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.17%, the 6th percentile. Fixed in uu_printenv 0.6.0.
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.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
4.4
uutils coreutils printenv Security Inspection Bypass via UTF-8 Enforcement
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.
- Record
CVE-2026-35366- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-754
- Updated
- 2026-11-02
EUVDEUVD-2026-25014
4.4
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.
- Record
EUVD-2026-25014- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-7259-cwhx-3xx3
4.4
Duplicate Advisory: uutils coreutils has an Improper Check for Unusual or Exceptional Conditions
Duplicate Advisory
This advisory has been withdrawn because it is a duplicate of GHSA-p7h3-7q52-72w8. This link is maintained to preserve external references.
Original 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.
- Record
GHSA-7259-cwhx-3xx3- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-754
- Updated
- 2026-11-02
GitHub AdvisoriesGHSA-p7h3-7q52-72w8
4.4
printenv: environment variables with invalid UTF-8 are silently skipped (evades inspection)
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.
Zellic finding 3.66. Reported in the Zellic uutils coreutils Program Security Assessment (for Canonical, Jan 2026), audited commit 3a07ffc5a9bd4c283e75afa548ba1f1957bad242.
- Record
GHSA-p7h3-7q52-72w8- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-116, CWE-754
- Updated
- 2026-11-02
NVD
4.4
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.
- Record
CVE-2026-35366- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-754
- Updated
- 2026-11-02
OSV
4.4
uutils coreutils printenv Security Inspection Bypass via UTF-8 Enforcement
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.
- Record
CVE-2026-35366- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-754
- Updated
- 2026-11-02
Show 4 moreShow less
OSVDEBIAN-CVE-2026-35366
4.4
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.
- Record
DEBIAN-CVE-2026-35366- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N - Updated
- 2026-11-02
OSVGHSA-7259-cwhx-3xx3
4.4
Duplicate Advisory: uutils coreutils has an Improper Check for Unusual or Exceptional Conditions
Duplicate Advisory
This advisory has been withdrawn because it is a duplicate of GHSA-p7h3-7q52-72w8. This link is maintained to preserve external references.
Original 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.
- Record
GHSA-7259-cwhx-3xx3- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-754
- Updated
- 2026-11-02
OSVGHSA-p7h3-7q52-72w8
4.4
printenv: environment variables with invalid UTF-8 are silently skipped (evades inspection)
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.
Zellic finding 3.66. Reported in the Zellic uutils coreutils Program Security Assessment (for Canonical, Jan 2026), audited commit 3a07ffc5a9bd4c283e75afa548ba1f1957bad242.
- Record
GHSA-p7h3-7q52-72w8- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-116, CWE-754
- Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-35366
4.4
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.
- Record
UBUNTU-CVE-2026-35366- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
uu_printenvcrates.io |
before 0.6.0 | 0.6.0 |
rust-coreutilsDebian:12 |
All versions, plus listed versions 0.0.17-20.0.17-30.0.17-40.0.17-50.0.17-6 Show 39 moreShow less0.0.19-10.0.19-20.0.19-30.0.20-10.0.21-10.0.22-10.0.23-10.0.23-20.0.23-30.0.24-10.0.24-20.0.26-10.0.26-20.0.26-30.0.26-40.0.26-50.0.27-10.0.27-20.0.27-30.0.30-10.0.30-20.0.30-30.0.30-3~exp10.0.30-40.10.0-10.11.0-10.11.0-20.12.0-10.6.0-10.7.0-10.8.0-10.8.0-20.8.0-30.8.0-40.8.0-50.8.0-60.9.0-10.9.0-20.9.0-3 |
None known |
rust-coreutilsDebian:13 |
All versions, plus listed versions 0.0.30-20.0.30-30.0.30-3~exp10.0.30-40.10.0-1 Show 14 moreShow less0.11.0-10.11.0-20.12.0-10.6.0-10.7.0-10.8.0-10.8.0-20.8.0-30.8.0-40.8.0-50.8.0-60.9.0-10.9.0-20.9.0-3 |
None known |
rust-coreutilsDebian:14 |
before 0.6.0-1, plus listed versions 0.0.30-20.0.30-30.0.30-3~exp10.0.30-4 |
0.6.0-1 |
rust-coreutilsUbuntu:24.04:LTS |
All versions, plus listed versions 0.0.20-10.0.22-10.0.23-10.0.23-20.0.23-30.0.24-10.0.24-2 |
None known |
rust-coreutilsUbuntu:25.10 |
All versions, plus listed versions 0.0.30-10.0.30-20.0.30-2ubuntu20.1.0-0ubuntu10.1.0+git20250711.2ba3a33-0ubuntu1 Show 11 moreShow less0.1.0+git20250711.2ba3a33-0ubuntu20.1.0+git20250711.2ba3a33-0ubuntu30.1.0+git20250711.2ba3a33-0ubuntu40.1.0+git20250801.cf79675-0ubuntu10.1.0+git20250813.4af2a84-0ubuntu20.1.0+git20250813.4af2a84-0ubuntu40.1.0+git20250813.4af2a84-0ubuntu60.1.0+git20250813.4af2a84-0ubuntu70.2.2-0ubuntu10.2.2-0ubuntu20.2.2-0ubuntu2.1 |
None known |
History
| When | Changed | Sources |
|---|---|---|
| 2026-11-03 | affected | |
| 2026-11-02 | created | CVE List, EUVD, GitHub Advisories, NVD, OSV |
References
github.com/uutils/coreutils/issues/9701
github.com/uutils/coreutils/pull/9728
github.com/uutils/coreutils/releases/tag/0.6.0
nvd.nist.gov/vuln/detail/CVE-2026-35366
github.com/uutils/coreutils/commit/0bfbbc00c7895c0fb6ea94987b4aab99e3d7ee52
github.com/advisories/GHSA-7259-cwhx-3xx3
Show 8 moreShow less
github.com/uutils/coreutils/security/advisories/GHSA-p7h3-7q52-72w8
github.com/advisories/GHSA-p7h3-7q52-72w8
github.com/uutils
github.com/CVEProject/cvelistV5/tree/main/cves/2026/35xxx/CVE-2026-35366.json
github.com/uutils/coreutils
security-tracker.debian.org/tracker/CVE-2026-35366
ubuntu.com/security/CVE-2026-35366
cve.org/CVERecord?id=CVE-2026-35366