CVE-2026-35338: chmod --preserve-root Bypassed By Any Path Vulnerability

HIGH
Advisory Identifier: GHSA-4c7q-4928-8445
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CVSS 7.3
CWE-59 CWE-22
Published
Advisory Summary

CVE-2026-35338 is a HIGH (CVSS 7.3) --preserve-root bypassed by any path vulnerability (CWE-59: Improper Link Resolution Before File Access ('Link Following')) affecting chmod libraries in the crates.io ecosystem. The issue involves --preserve-root bypassed by any path that resolves to root (e.g. /../). Remediation is available by upgrading affected packages to version 0.6.0.

CVE-2026-35338 at a Glance

CVE Identifier CVE-2026-35338
GHSA Identifier GHSA-4c7q-4928-8445
Severity HIGH
CVSS v3.1 Base Score 7.3
CWE Classification CWE-59: Improper Link Resolution Before File Access ('Link Following')
Affected Product chmod
Package Ecosystem crates.io
Published Date
Last Updated

Security Impact

CVSS: 7.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H).

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-35338

To remediate this vulnerability, upgrade all affected chmod dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

uu_chmod fixed: 0.6.0 
Upgrade uu_chmod to 0.6.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for uu_chmod

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-35338, inspect your project dependencies for chmod:

inspect dependencies for uu_chmod

Analyze the terminal output to locate any version of chmod in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.6.0), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-59: Improper Link Resolution Before File Access ('Link Following'), where the product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource. In chmod, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

`Chmoder::chmod()` only compares the literal argument against `Path::new("/")`, so the `--preserve-root` guard is bypassed by any path that *resolves* to root — a symlink to `/` or simply `/../`. ``` if self.recursive && self.preserve_root && file == Path::new("/") { return Err(ChmodError::PreserveRoot("/".to_string()).into()); } ``` **PoC** — recursively chmods the entire filesystem to `000` despite `--preserve-root`: ``` chmod -R --preserve-root 000 /../ -v ``` **Impact:** `--preserve-root` is the documented safeguard against destructive recursive operations on `/`. Bypassing it allows `chmod -R` to alter permissions across the whole filesystem, causing a complete system breakdown. Recommendation: canonicalize the target path before comparing against root. **Remediation:** Acknowledged by Canonical; fixed in commit 413055b3. --- _Reported by Zellic in the *uutils coreutils Program Security Assessment* (prepared for Canonical, Jan 20 2026), audited commit `3a07ffc5a9bd4c283e75afa548ba1f1957bad242`. Finding 3.1. Credit: Zellic._

CVE-2026-35338 Affected chmod Versions

1 component(s)
Fixed Versions:
0.6.0
Product / Package Ecosystem Affected Versions Fixed Version
uu_chmod
 crates.io
< 0.6.0
0.6.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/uutils/coreutils/security/advisories/GHSA-4c7q-4928-8445
NVD — CVE-2026-35338 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-35338
chmod Source Repository REPOSITORY
https://github.com/uutils/coreutils/pull/10033
Security Fix Commit FIX COMMIT
https://github.com/uutils/coreutils/commit/413055b378fa6fe2299c5e5f538c8e6e841ab810
chmod Source Repository REPOSITORY
https://github.com/uutils/coreutils
chmod Release RELEASE
https://github.com/uutils/coreutils/releases/tag/0.6.0

Frequently Asked Questions

What is CVE-2026-35338?
CVE-2026-35338 is a security vulnerability in chmod involving --preserve-root bypassed by any path that resolves to root (e.g. /../) under CWE-59: Improper Link Resolution Before File Access ('Link Following').
Which chmod versions are affected?
Affected versions include releases prior to 0.6.0 across affected packages: uu_chmod.
What version fixes CVE-2026-35338?
Upgrading to 0.6.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is uu_chmod affected?
Yes, uu_chmod is affected in releases prior to 0.6.0. Upgrade your dependency to 0.6.0 or later.
What is the CVSS score of CVE-2026-35338?
CVE-2026-35338 has a CVSS v3.1 base score of 7.3 (HIGH) with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-35338?
CVE-2026-35338 is classified under CWE-59: Improper Link Resolution Before File Access ('Link Following') (The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.).
How can I check crates.io dependencies for CVE-2026-35338?
Run the dependency tree command: 'inspect dependencies for uu_chmod'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-4c7q-4928-8445",
  "modified" : "2026-07-06T17:41:45Z",
  "published" : "2026-07-06T17:41:45Z",
  "aliases" : [ "CVE-2026-35338" ],
  "summary" : "chmod: --preserve-root bypassed by any path that resolves to root (e.g. /../)",
  "details" : "`Chmoder::chmod()` only compares the literal argument against `Path::new(\"/\")`, so the `--preserve-root` guard is bypassed by any path that *resolves* to root — a symlink to `/` or simply `/../`.\n\n```\nif self.recursive && self.preserve_root && file == Path::new(\"/\") {\n    return Err(ChmodError::PreserveRoot(\"/\".to_string()).into());\n}\n```\n\n**PoC** — recursively chmods the entire filesystem to `000` despite `--preserve-root`:\n\n```\nchmod -R --preserve-root 000 /../ -v\n```\n\n**Impact:** `--preserve-root` is the documented safeguard against destructive recursive operations on `/`. Bypassing it allows `chmod -R` to alter permissions across the whole filesystem, causing a complete system breakdown. Recommendation: canonicalize the target path before comparing against root.\n\n**Remediation:** Acknowledged by Canonical; fixed in commit 413055b3.\n\n---\n_Reported by Zellic in the *uutils coreutils Program Security Assessment* (prepared for Canonical, Jan 20 2026), audited commit `3a07ffc5a9bd4c283e75afa548ba1f1957bad242`. Finding 3.1. Credit: Zellic._",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "uu_chmod"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.6.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/uutils/coreutils/security/advisories/GHSA-4c7q-4928-8445"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-35338"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/uutils/coreutils/pull/10033"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/uutils/coreutils/commit/413055b378fa6fe2299c5e5f538c8e6e841ab810"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/uutils/coreutils"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/uutils/coreutils/releases/tag/0.6.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-22", "CWE-59" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-06T17:41:45Z",
    "nvd_published_at" : null
  }
}