CVE-2026-35341: mkfifo Permissions Of An Existing File Vulnerability

HIGH
Advisory Identifier: GHSA-pmf6-rcx4-v53v
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CVSS 7.1
CWE-732 CWE-281
Published
Advisory Summary

CVE-2026-35341 is a HIGH (CVSS 7.1) permissions of an existing file vulnerability (CWE-732: Incorrect Permission Assignment for Critical Resource) affecting mkfifo libraries in the crates.io ecosystem. The issue involves permissions of an existing file are changed after fifo creation fails. Remediation is available by upgrading affected packages to version 0.6.0.

CVE-2026-35341 at a Glance

CVE Identifier CVE-2026-35341
GHSA Identifier GHSA-pmf6-rcx4-v53v
Severity HIGH
CVSS v3.1 Base Score 7.1
CWE Classification CWE-732: Incorrect Permission Assignment for Critical Resource
Affected Product mkfifo
Package Ecosystem crates.io
Published Date
Last Updated

Security Impact

CVSS: 7.1

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:H/I:H/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 High (C:H)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2026-35341

To remediate this vulnerability, upgrade all affected mkfifo 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_mkfifo fixed: 0.6.0 
Upgrade uu_mkfifo 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_mkfifo

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-35341, inspect your project dependencies for mkfifo:

inspect dependencies for uu_mkfifo

Analyze the terminal output to locate any version of mkfifo 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-732: Incorrect Permission Assignment for Critical Resource, where the product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors. In mkfifo, 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

When `mkfifo()` fails (e.g. target already exists), the code shows an error but is missing a `continue;`, so it falls through to `fs::set_permissions` and changes the permissions of the pre-existing file to the default FIFO mode (`0o666` & umask -> `0644`). ``` $ touch secret; chmod 000 secret $ coreutils mkfifo secret fifo3 fifo4 mkfifo: cannot create fifo 'secret': File exists $ ll secret # uutils: prw-r--r-- secret # changed to 644 (GNU leaves it 000) ``` **Impact:** an attacker (or user error) can relax permissions on sensitive owner-only files such as SSH private keys, exposing them to other users. Recommendation: add `continue;` after the error. **Remediation:** Acknowledged by Canonical; fixed in PR #10376. --- _Reported by Zellic in the *uutils coreutils Program Security Assessment* (prepared for Canonical, Jan 20 2026), audited commit `3a07ffc5a9bd4c283e75afa548ba1f1957bad242`. Finding 3.8. Credit: Zellic._ _Upstream tracking issue: https://github.com/uutils/coreutils/issues/10020 · CVE-2026-35341_

CVE-2026-35341 Affected mkfifo Versions

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

References

GitHub Advisory / Wiki ADVISORY
https://github.com/uutils/coreutils/security/advisories/GHSA-pmf6-rcx4-v53v
NVD — CVE-2026-35341 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-35341
mkfifo Source Repository REPOSITORY
https://github.com/uutils/coreutils/issues/10020
mkfifo Source Repository REPOSITORY
https://github.com/uutils/coreutils/pull/10376
mkfifo Source Repository REPOSITORY
https://github.com/uutils/coreutils

Frequently Asked Questions

What is CVE-2026-35341?
CVE-2026-35341 is a security vulnerability in mkfifo involving permissions of an existing file are changed after FIFO creation fails under CWE-732: Incorrect Permission Assignment for Critical Resource.
Which mkfifo versions are affected?
Affected versions include releases prior to 0.6.0 across affected packages: uu_mkfifo.
What version fixes CVE-2026-35341?
Upgrading to 0.6.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is uu_mkfifo affected?
Yes, uu_mkfifo 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-2026-35341?
CVE-2026-35341 has a CVSS v3.1 base score of 7.1 (HIGH) with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.
What CWE is associated with CVE-2026-35341?
CVE-2026-35341 is classified under CWE-732: Incorrect Permission Assignment for Critical Resource (The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.).
How can I check crates.io dependencies for CVE-2026-35341?
Run the dependency tree command: 'inspect dependencies for uu_mkfifo'. 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-pmf6-rcx4-v53v",
  "modified" : "2026-07-06T21:53:34Z",
  "published" : "2026-07-06T21:53:34Z",
  "aliases" : [ "CVE-2026-35341" ],
  "summary" : "mkfifo: permissions of an existing file are changed after FIFO creation fails",
  "details" : "When `mkfifo()` fails (e.g. target already exists), the code shows an error but is missing a `continue;`, so it falls through to `fs::set_permissions` and changes the permissions of the pre-existing file to the default FIFO mode (`0o666` & umask -> `0644`).\n\n```\n$ touch secret; chmod 000 secret\n$ coreutils mkfifo secret fifo3 fifo4\nmkfifo: cannot create fifo 'secret': File exists\n$ ll secret      # uutils:\nprw-r--r-- secret   # changed to 644 (GNU leaves it 000)\n```\n\n**Impact:** an attacker (or user error) can relax permissions on sensitive owner-only files such as SSH private keys, exposing them to other users. Recommendation: add `continue;` after the error.\n\n**Remediation:** Acknowledged by Canonical; fixed in PR #10376.\n\n---\n_Reported by Zellic in the *uutils coreutils Program Security Assessment* (prepared for Canonical, Jan 20 2026), audited commit `3a07ffc5a9bd4c283e75afa548ba1f1957bad242`. Finding 3.8. Credit: Zellic._\n\n_Upstream tracking issue: https://github.com/uutils/coreutils/issues/10020 · CVE-2026-35341_",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "uu_mkfifo"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.6.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/uutils/coreutils/security/advisories/GHSA-pmf6-rcx4-v53v"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-35341"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/uutils/coreutils/issues/10020"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/uutils/coreutils/pull/10376"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/uutils/coreutils"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-281", "CWE-732" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-06T21:53:34Z",
    "nvd_published_at" : null
  }
}