CVE-2026-35353: mkdir -m Exposes Directory With Umask Vulnerability

LOW
Advisory Identifier: GHSA-mj6p-44ch-cq69
Share
CVSS 3.3
CWE-362 CWE-367 CWE-732
Published
Advisory Summary

CVE-2026-35353 is a LOW (CVSS 3.3) -m exposes directory with umask vulnerability (CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')) affecting mkdir libraries in the crates.io ecosystem. The issue involves -m exposes directory with umask perms before chmod (race window). Remediation is available by upgrading affected packages to version 0.6.0.

CVE-2026-35353 at a Glance

CVE Identifier CVE-2026-35353
GHSA Identifier GHSA-mj6p-44ch-cq69
Severity LOW
CVSS v3.1 Base Score 3.3
CWE Classification CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Affected Product mkdir
Package Ecosystem crates.io
Published Date
Last Updated

Security Impact

CVSS: 3.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N).

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-35353

To remediate this vulnerability, upgrade all affected mkdir dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

uu_mkdir fixed: 0.6.0 
Upgrade uu_mkdir to 0.6.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for uu_mkdir

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-35353, inspect your project dependencies for mkdir:

inspect dependencies for uu_mkdir

Analyze the terminal output to locate any version of mkdir in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.6.0), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition'), where the product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently. In mkdir, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

The mkdir utility in uutils coreutils incorrectly applies permissions when using the -m flag by creating a directory with umask-derived permissions (typically 0755) before subsequently changing them to the requested mode via a separate chmod system call. In multi-user environments, this introduces a brief window where a directory intended to be private is accessible to other users, potentially leading to unauthorized data access. --- _Zellic finding 3.48. Reported in the Zellic *uutils coreutils Program Security Assessment* (for Canonical, Jan 2026), audited commit `3a07ffc5a9bd4c283e75afa548ba1f1957bad242`._

CVE-2026-35353 Affected mkdir Versions

1 component(s)
Fixed Versions:
0.6.0
Product / Package Ecosystem Affected Versions Fixed Version
uu_mkdir
 crates.io
< 0.6.0
0.6.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/uutils/coreutils/security/advisories/GHSA-mj6p-44ch-cq69
NVD — CVE-2026-35353 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-35353
mkdir Source Repository REPOSITORY
https://github.com/uutils/coreutils/pull/10036
Security Fix Commit FIX COMMIT
https://github.com/uutils/coreutils/commit/037b9583bc03d814e8516df54ebcda6f681fe1f8
mkdir Source Repository REPOSITORY
https://github.com/uutils/coreutils
mkdir Release RELEASE
https://github.com/uutils/coreutils/releases/tag/0.6.0

Frequently Asked Questions

What is CVE-2026-35353?
CVE-2026-35353 is a security vulnerability in mkdir involving -m exposes directory with umask perms before chmod (race window) under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition').
Which mkdir versions are affected?
Affected versions include releases prior to 0.6.0 across affected packages: uu_mkdir.
What version fixes CVE-2026-35353?
Upgrading to 0.6.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is uu_mkdir affected?
Yes, uu_mkdir is affected in releases prior to 0.6.0. Upgrade your dependency to 0.6.0 or later.
What is the CVSS score of CVE-2026-35353?
CVE-2026-35353 has a CVSS v3.1 base score of 3.3 (LOW) with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2026-35353?
CVE-2026-35353 is classified under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') (The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.).
How can I check crates.io dependencies for CVE-2026-35353?
Run the dependency tree command: 'inspect dependencies for uu_mkdir'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-mj6p-44ch-cq69",
  "modified" : "2026-07-06T20:16:16Z",
  "published" : "2026-07-06T20:16:16Z",
  "aliases" : [ "CVE-2026-35353" ],
  "summary" : "mkdir: -m exposes directory with umask perms before chmod (race window)",
  "details" : "The mkdir utility in uutils coreutils incorrectly applies permissions when using the -m flag by creating a directory with umask-derived permissions (typically 0755) before subsequently changing them to the requested mode via a separate chmod system call. In multi-user environments, this introduces a brief window where a directory intended to be private is accessible to other users, potentially leading to unauthorized data access.\n\n---\n_Zellic finding 3.48. Reported in the Zellic *uutils coreutils Program Security Assessment* (for Canonical, Jan 2026), audited commit `3a07ffc5a9bd4c283e75afa548ba1f1957bad242`._",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "uu_mkdir"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.6.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/uutils/coreutils/security/advisories/GHSA-mj6p-44ch-cq69"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-35353"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/uutils/coreutils/pull/10036"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/uutils/coreutils/commit/037b9583bc03d814e8516df54ebcda6f681fe1f8"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/uutils/coreutils"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/uutils/coreutils/releases/tag/0.6.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-362", "CWE-367", "CWE-732" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-06T20:16:16Z",
    "nvd_published_at" : null
  }
}