uutils coreutils chcon Security Bypass and Mandatory Access Control (MAC) Inconsistency via TOCTOU Race Condition
A Time-of-Check to Time-of-Use (TOCTOU) vulnerability exists in the chcon utility of uutils coreutils during recursive operations. The implementation resolves recursive targets using a fresh path lookup (via fts_accpath) rather than binding the traversal and label application to the specific directory state encountered during traversal. Because these operations are not anchored to file descriptors, a local attacker with write access to a directory tree can exploit timing-sensitive rename or symbolic link races to redirect a privileged recursive relabeling operation to unintended files or directories. This vulnerability breaks the hardening expectations for SELinux administration workflows and can lead to the unauthorized modification of security labels on sensitive system objects.
- Published
- Apr 22, 2026
- Updated
- Jun 17, 2026
- EPSS
- 0.1% · 1th percentile
- CWE
- CWE-367
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Report tools
Action score
23
Monitor
Low priority for now.
- CVSS
- 23 / 40 · 5.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.1%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 5.8
- CNA · canonical
- 4.5
- 1.3 point gap
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| uutils | coreutils | cpe:2.3:a:uutils:coreutils |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- uutils coreutilsbefore 0.8.0
Versions reported by the vendor
Affected version ranges reported by the assigning authority (canonical). Independent of NVD's CPE analysis and usually ahead of it.
Uutils coreutils
- before 0.8.0affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| crates.io | coreutils | up to and including 0.8.0 | — |
| Debian:12 | rust-coreutils | all versions | — |
| Debian:14 | rust-coreutils | before 0.10.0-1 | 0.10.0-1 |
Same product
uutils: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-35368uutils coreutils chroot Local Privilege Escalation and chroot Escape in via Name Service Switch (NSS) Injection31Monitor
- CVE-2026-35349uutils coreutils Path-Based Safety Bypass with --preserve-root30Monitor
- CVE-2026-93658uutils coreutils 0.0.18 before 0.10.0 Privilege Escalation via setuid29Monitor
- CVE-2026-35338uutils coreutils chmod Path Traversal Bypass of --preserve-root29Monitor
- CVE-2026-35352uutils coreutils mkfifo Privilege Escalation via TOCTOU Race Condition28Monitor
- CVE-2026-35341uutils coreutils mkfifo Unauthorized Permission Change on Existing Files28Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Uutils coreutils | 0.8.0 | Vendor (CNA) |
| debian:rust-coreutils | 0.10.0-1 · Debian:14 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- Zellicfinder
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-353520 days apartuutils coreutils mkfifo Privilege Escalation via TOCTOU Race Condition28Monitor
- CVE-2026-353550 days apartuutils coreutils install Arbitrary File Overwrite via Symlink TOCTOU Race25Monitor
- CVE-2026-353560 days apartuutils coreutils install Arbitrary File Overwrite with -D via Path Component Symlink Race25Monitor
- CVE-2026-353600 days apartuutils coreutils touch Arbitrary File Truncation via TOCTOU Race Condition25Monitor
- CVE-2026-353640 days apartuutils coreutils mv Arbitrary File Overwrite via Cross-Device TOCTOU Race Condition25Monitor
- CVE-2026-353740 days apartuutils coreutils split Arbitrary File Truncation via Time-of-Check to Time-of-Use (TOCTOU) Race Condition25Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- low · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- low · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- High
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- Low
- Integrity impact
- High
- Availability impact
- Low
Weakness class (CWE)
CWE-367 · Time-of-check Time-of-use (TOCTOU) Race ConditionCVSS vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
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References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.