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GHSA-PMF6-RCX4-V53V

Vulnerability from github – Published: 2026-07-06 21:53 – Updated: 2026-07-06 21:53

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).

$ 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

Severity

7.1 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

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{
  "affected": [
    {
      "package": {
        "ecosystem": "crates.io",
        "name": "uu_mkfifo"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.6.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-35341"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-281",
      "CWE-732"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-06T21:53:34Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "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` \u0026 umask -\u003e `0644`).\n\n```\n$ touch secret; chmod 000 secret\n$ coreutils mkfifo secret fifo3 fifo4\nmkfifo: cannot create fifo \u0027secret\u0027: 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 \u00b7 CVE-2026-35341_",
  "id": "GHSA-pmf6-rcx4-v53v",
  "modified": "2026-07-06T21:53:34Z",
  "published": "2026-07-06T21:53:34Z",
  "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"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "mkfifo: permissions of an existing file are changed after FIFO creation fails"
}

CVE-2026-35341 (GCVE-0-2026-35341)

Vulnerability from cvelistv5 – Published: 2026-04-22 16:07 – Updated: 2026-04-24 13:43

Title

uutils coreutils mkfifo Unauthorized Permission Change on Existing Files

Summary

A vulnerability in uutils coreutils mkfifo allows for the unauthorized modification of permissions on existing files. When mkfifo fails to create a FIFO because a file already exists at the target path, it fails to terminate the operation for that path and continues to execute a follow-up set_permissions call. This results in the existing file's permissions being changed to the default mode (often 644 after umask), potentially exposing sensitive files such as SSH private keys to other users on the system.

Severity

7.1 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-04-24 03:55 UTC

CWE

CWE-732 - Incorrect Permission Assignment for Critical Resource

Assigner

canonical mitre root

References

1 reference

URL	Tags
https://github.com/uutils/coreutils/issues/10020	issue-tracking

Impacted products

1 product

Vendor	Product	Version
Uutils	coreutils

Credits

Zellic

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-35341",
                "options": [
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                    "Exploitation": "none"
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                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-04-24T03:55:23.826443Z",
                "version": "2.0.3"
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        "providerMetadata": {
          "dateUpdated": "2026-04-24T13:43:36.473Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
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          "collectionURL": "https://github.com/uutils",
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            "Unix",
            "macOS"
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          "repo": "https://github.com/uutils/coreutils",
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          "type": "finder",
          "value": "Zellic"
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      "descriptions": [
        {
          "lang": "en",
          "value": "A vulnerability in uutils coreutils mkfifo allows for the unauthorized modification of permissions on existing files. When mkfifo fails to create a FIFO because a file already exists at the target path, it fails to terminate the operation for that path and continues to execute a follow-up set_permissions call. This results in the existing file\u0027s permissions being changed to the default mode (often 644 after umask), potentially exposing sensitive files such as SSH private keys to other users on the system."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-180",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-180: Exploiting Incorrectly Configured Access Control Security Levels"
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      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "NONE",
            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
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    "dateReserved": "2026-04-02T12:58:56.087Z",
    "dateUpdated": "2026-04-24T13:43:36.473Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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GHSA-PMF6-RCX4-V53V

CVE-2026-35341 (GCVE-0-2026-35341)

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