uutils coreutils mkfifo Unauthorized Permission Change on Existing Files

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

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.

Source published

22 Apr 2026 16:07:39 UTC

Source modified

24 Apr 2026 13:43:36 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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CVSS 3.1 · 7.1 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

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.

Source published

Apr 22, 2026, 4:07:39 PM (timezone not stated)

Source modified

Apr 24, 2026, 1:43:36 PM (timezone not stated)

Observed here

1 Nov 2026 06:08:33 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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EUVD CVSS 3.1 · 7.1 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

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.

Source published

22 Apr 2026 17:16:36 UTC

Source modified

26 Oct 2026 22:10:00 UTC

Observed here

27 Oct 2026 09:03:12 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 7.1 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

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_

Source published

6 Jul 2026 21:53:34 UTC

Source modified

6 Jul 2026 22:11:26 UTC

Observed here

24 Oct 2026 13:19:54 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Publisher rating · HIGH