Skip to main content

Boteraser | Website and Server Security Solutions

🛡️ CVE-2026-35355 — coreutils

🟡 CVSS 6.3 — Medium ⚠️ Exploit Public CWE-367 OSV
6.3
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

install: TOCTOU symlink race (unlink-then-create without O_EXCL) allows arbitrary file overwrite

copy_file in install/src/install.rs removes the destination then recreates it by pathname via File::create / fs::copy without O_EXCL/create_new. Between the unlink and the recreate, a local attacker with write access to the destination directory can drop in a symlink and redirect the write.

Impact: when install runs privileged into an attacker-writable directory (staging/build paths), the race allows redirecting writes to arbitrary files and overwriting sensitive system files (/etc/passwd, /etc/shadow). Recommendation: create atomically with create_new/O_EXCL and copy via the opened fd rather than reopening by path.

Remediation: Acknowledged by Canonical; fixed in commit b5bbabc1.

_Reported by Zellic in the *uutils coreutils Program Security Assessment* (prepared for Canonical, Jan 20 2026), audited commit 3a07ffc5a9bd4c283e75afa548ba1f1957bad242. Finding 3.50. Credit: Zellic._

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is high, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity high, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H

  • Attack vector: Local — a local account, shell or session on the host is needed.
  • Attack complexity: High — the attacker first has to win a race, learn a secret or otherwise prepare the target.
  • Privileges required: Low — an ordinary user account is enough.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: None.
  • Integrity impact: High — total loss, or loss the attacker controls.
  • Availability impact: High — total loss, or loss the attacker controls.

Weakness class

CVE-2026-35355 is classified as CWE-367: Time-of-check Time-of-use Race Condition. The state checked and the state acted upon can differ, because it may change between the two steps.

Affected software

CVE-2026-35355 is recorded against 2 packages.

  • coreutils
  • uu-install

Timeline and source

Published on 22 April 2026 and last revised on 6 July 2026. A public exploit is known to exist, which raises the urgency of patching considerably. A vendor advisory or fix has been published. Record sourced from OSV.

References

nvd.nist.gov (Advisory)
github.com (Web)
github.com (Web)
github.com (Package)
github.com (Web)

Other advisories for this package

coreutils has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-367: Time-of-check Time-of-use Race Condition) in other software:

CVE-2026-35355 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity MEDIUM
CVSS Score 6.3
CVSS Vector CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H
CWE CWE-367
Public Exploit ⚠️ Yes
Source OSV
Published 2026-04-22
Updated 2026-08-20
Modified 2026-07-06

Affected Packages

Software From version Fixed in
coreutils — —
uu-install — —

Similar Threats

Exploit Protection

Are you running coreutils?

CVE-2026-35355 carries CVSS 6.3 Medium rating and a public exploit already exists. BotEraser checks your installation against this and other known CVE records, and blocks IPs associated with exploit activity.

Check My Site For CVE-2026-35355 →

No credit card required  ·  Results in minutes

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

Browse related advisories

All advisoriesCVECVE 2026
✓