CVE-2026-35373: Uu ln Remote Code Execution Vulnerability

LOW
Advisory Identifier: GHSA-jcjr-rh8q-7xqf
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CVSS 3.3
CWE-176
Published
Advisory Summary

CVE-2026-35373 is a LOW (CVSS 3.3) remote code execution vulnerability (CWE-176: Improper Handling of Unicode Encoding) affecting Uu ln libraries in the crates.io ecosystem. The issue involves rejects non-utf-8 source filenames in target-directory mode. Remediation is available by upgrading affected packages to version 0.6.0.

CVE-2026-35373 at a Glance

CVE Identifier CVE-2026-35373
GHSA Identifier GHSA-jcjr-rh8q-7xqf
Severity LOW
CVSS v3.1 Base Score 3.3
CWE Classification CWE-176: Improper Handling of Unicode Encoding
Affected Product Uu ln
Package Ecosystem crates.io
Published Date
Last Updated

Security Impact

CVSS: 3.3

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:N/S:U/C:N/I:N/A:L).

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability Low (A:L)

How to Fix CVE-2026-35373

To remediate this vulnerability, upgrade all affected Uu ln 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_ln fixed: 0.6.0 
Upgrade uu_ln 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_ln

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-35373, inspect your project dependencies for Uu ln:

inspect dependencies for uu_ln

Analyze the terminal output to locate any version of Uu ln 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-176: Improper Handling of Unicode Encoding, where the product does not properly handle when an input contains unicode encoding. In Uu ln, 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

In target-directory forms (`ln SOURCE... DIRECTORY`), `ln` rejects source paths with non-UTF-8 filename bytes, while GNU accepts them. Breaks GNU compatibility for byte-oriented filenames on Unix filesystems. PoC: ``` name=$(printf 'bad_\377'); mkdir dst; : > "$name"; ln "$name" dst # GNU: exit 0, creates dst/bad_\377 ; uutils: exit 1, dst empty ``` --- _Zellic private finding (zellic-ext/coreutils-private PR #84). Reported in the Zellic *uutils coreutils Program Security Assessment* (for Canonical, Jan 2026), audited commit `3a07ffc5a9bd4c283e75afa548ba1f1957bad242`._

CVE-2026-35373 Affected Uu ln Versions

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

References

GitHub Advisory / Wiki ADVISORY
https://github.com/uutils/coreutils/security/advisories/GHSA-jcjr-rh8q-7xqf
NVD — CVE-2026-35373 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-35373
Uu ln Source Repository REPOSITORY
https://github.com/uutils/coreutils/pull/11403
Uu ln Source Repository REPOSITORY
https://github.com/uutils/coreutils

Frequently Asked Questions

What is CVE-2026-35373?
CVE-2026-35373 is a security vulnerability in Uu ln involving rejects non-UTF-8 source filenames in target-directory mode under CWE-176: Improper Handling of Unicode Encoding.
Which Uu ln versions are affected?
Affected versions include releases prior to 0.6.0 across affected packages: uu_ln.
What version fixes CVE-2026-35373?
Upgrading to 0.6.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is uu_ln affected?
Yes, uu_ln 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-2026-35373?
CVE-2026-35373 has a CVSS v3.1 base score of 3.3 (LOW) with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L.
What CWE is associated with CVE-2026-35373?
CVE-2026-35373 is classified under CWE-176: Improper Handling of Unicode Encoding (The product does not properly handle when an input contains Unicode encoding.).
How can I check crates.io dependencies for CVE-2026-35373?
Run the dependency tree command: 'inspect dependencies for uu_ln'. 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-jcjr-rh8q-7xqf",
  "modified" : "2026-07-06T19:53:39Z",
  "published" : "2026-07-06T19:53:39Z",
  "aliases" : [ "CVE-2026-35373" ],
  "summary" : "ln: rejects non-UTF-8 source filenames in target-directory mode",
  "details" : "In target-directory forms (`ln SOURCE... DIRECTORY`), `ln` rejects source paths with non-UTF-8 filename bytes, while GNU accepts them. Breaks GNU compatibility for byte-oriented filenames on Unix filesystems.\n\nPoC:\n```\nname=$(printf 'bad_\\377'); mkdir dst; : > \"$name\"; ln \"$name\" dst\n# GNU: exit 0, creates dst/bad_\\377 ; uutils: exit 1, dst empty\n```\n\n---\n_Zellic private finding (zellic-ext/coreutils-private PR #84). Reported in the Zellic *uutils coreutils Program Security Assessment* (for Canonical, Jan 2026), audited commit `3a07ffc5a9bd4c283e75afa548ba1f1957bad242`._",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "uu_ln"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.6.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/uutils/coreutils/security/advisories/GHSA-jcjr-rh8q-7xqf"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-35373"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/uutils/coreutils/pull/11403"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/uutils/coreutils"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-176" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-06T19:53:39Z",
    "nvd_published_at" : null
  }
}