CVE-2026-35356: uutils coreutils symlink race in install -D directory creation

CVE-2026-35356 · Severity: medium · CVSS 6.3 · Published 2026-04-22

A vulnerability in the 'install' utility of the Rust-based uutils coreutils allows a local attacker to overwrite arbitrary files on the system. By exploiting a timing window during directory creation, an attacker can redirect file writes to unintended locations, such as sensitive system files. This could lead to a complete system compromise if the utility is run with elevated (root) privileges.

Technologies: Uutils Coreutils. Vendors: crates.io, Uutils.

Quick answers

Is CVE-2026-35356 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-35356 being exploited in the wild.
How severe is CVE-2026-35356?
Medium severity, with a CVSS score of 6.3, published 22 April 2026.
Which products and versions are affected?
uu_install (crates.io) < 0.7.0, SEMVER:introduced=0,fixed=0.7.0.
Is there a fix for CVE-2026-35356?
Yes. uu_install (crates.io): upgrade to 0.7.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-35356 attacked?
It is attacked with local access, in a software library.
Am I affected by CVE-2026-35356?
Check whether you run uu_install (crates.io) or Uutils Coreutils at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • uu_install (crates.io): upgrade to 0.7.0 or later
    cargo update -p uu_install

Technical details

A Time-of-Check to Time-of-Use (TOCTOU) race condition exists in the `install` utility of `uutils/coreutils` when using the `-D` flag. The implementation uses `fs::create_dir_all` followed by path-based `File::create` or `fs::copy` operations, neither of which are anchored to a directory file descriptor. A local attacker with concurrent write access to the destination tree can replace a path component with a symbolic link between the directory creation and the file write. This redirects the privileged write to an arbitrary location on the filesystem. The fix involves migrating to `dirfd`-based operations (`openat`, `mkdirat`) with `O_NOFOLLOW` to ensure path resolution is securely anchored.

Affected products

  • uutils coreutils (uu_install) < 0.7.0

Identifiers

  • CVE-2026-35356
  • GHSA-gwm6-q8ch-hcfr

Timeline

  • 2026-01-09: other: Fix submitted via Pull Request 10140
  • 2026-01-20: disclosed: Reported by Zellic in security assessment
  • 2026-02-14: patched: Fix merged into main branch
  • 2026-05-30: advisory: Initial GitHub Advisory published
  • 2026-07-06: advisory: Advisory updated and reviewed

References

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