install -D: symlink race in directory creation allows arbitrary file overwrite

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-35356: 0.11% estimated exploitation activity in the next 30 days; percentile 1.17 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

The -D path runs fs::createdirall on a pathname then later opens the destination via path-based File::create/fs::copy, neither anchored to a directory fd. Between the two, an attacker can replace a path component with a symlink, redirecting the write. Impact: an attacker with concurrent write access to the destination tree can redirect a privileged install -D to an arbitrary location, enabling arbitrary file overwrite with attacker-controlled content. Recommendation: use dirfd-based traversal (openat/mkdirat + ONOFOLLOW) per component and create the destination via openat on the same dirfd. Remediation: Acknowledged by Canonical; fixed in commit 0c412999. --- Reported by Zellic in the uutils coreutils Program Security Assessment (prepared for Canonical, Jan 20 2026), audited commit 3a07ffc5a9bd4c283e75afa548ba1f1957bad242. Finding 3.51. Credit: Zellic.

Published by the source

6 Jul 2026, 19:54 UTC

Last modified by the source

6 Jul 2026, 19:54 UTC

Source last checked

26 Oct 2026, 15:43 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-gwm6-q8ch-hcfr

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# Patch Next advisory brief: CVE-2026-35356

Advisory: install -D: symlink race in directory creation allows arbitrary file overwrite
IDs: CVE-2026-35356, GHSA-gwm6-q8ch-hcfr
Record: https://patchnext.com/advisories/cve-2026-35356 (revision 1, source checked 26 Oct 2026, 15:43 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: uu_install 0.7.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io uu_install: affected < 0.7.0; fixed in 0.7.0

## Suggested inspection (read-only)
- crates.io uu_install: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on uu_install.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-gwm6-q8ch-hcfr (GitHub-reviewed advisory GHSA-gwm6-q8ch-hcfr lists affected ranges: crates.io uu_install >=0 <0.7.0)

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