GHSA-PMF6-RCX4-V53V

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



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