CVE-2025-62161: Youki Youki Container Escape Vulnerability

HIGH
Advisory Identifier: GHSA-4g74-7cff-xcv8
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CVSS 10.0
CWE-363 CWE-61
Published
Advisory Summary

CVE-2025-62161 is a HIGH (CVSS 10.0) youki container escape vulnerability (CWE-363: Race Condition Enabling Link Following) affecting Youki libraries in the crates.io ecosystem. The issue involves youki container escape via "masked path" abuse due to mount race conditions. Remediation is available by upgrading affected packages to version 0.5.7.

CVE-2025-62161 at a Glance

CVE Identifier CVE-2025-62161
GHSA Identifier GHSA-4g74-7cff-xcv8
Severity HIGH
CVSS v3.1 Base Score 10.0
CWE Classification CWE-363: Race Condition Enabling Link Following
Affected Product Youki
Package Ecosystem crates.io
Published Date
Last Updated

Security Impact

CVSS: 10.0

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

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2025-62161

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

youki fixed: 0.5.7 
Upgrade youki to 0.5.7
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 youki

How to Check if You Are Affected

To determine whether your application is affected by CVE-2025-62161, inspect your project dependencies for Youki:

inspect dependencies for youki

Analyze the terminal output to locate any version of Youki in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.5.7), 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-363: Race Condition Enabling Link Following, where the product checks the status of a file or directory before accessing it, which produces a race condition in which the file can be replaced with a link before the access is performed, causing the product to access the wrong file. In Youki, 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

### Impact ### youki utilizes bind mounting the container's `/dev/null` as a file mask. When performing this operation, the initial validation of the source `/dev/null` was insufficient. Specifically, we initially failed to verify whether `/dev/null` was genuinely present. However, we did perform validation to ensure that the `/dev/null` path existed within the container, including checking for symbolic links. Additionally, there was a vulnerability in the timing between validation and the actual mount operation. As a result, by replacing `/dev/null` with a symbolic link, we can bind-mount arbitrary files from the host system. This is a different project, but the core logic is similar to the CVE in runc. Issues were identified in runc, and verification was also conducted in youki to confirm the problems. https://github.com/opencontainers/runc/security/advisories/GHSA-9493-h29p-rfm2 ### Credits Thanks to Lei Wang (@ssst0n3 from Huawei) for finding and reporting the original runc's vulnerability (Attack 1), and Li Fubang (@lifubang from acmcoder.com, CIIC) for discovering another attack vector in runc (Attack 2) based on @ssst0n3's initial findings. Also, @cyphar helped youki in finding the problem.

CVE-2025-62161 Affected Youki Versions

1 component(s)
Fixed Versions:
0.5.7
Product / Package Ecosystem Affected Versions Fixed Version
youki
 crates.io
< 0.5.7
0.5.7

References

GitHub Advisory / Wiki ADVISORY
https://github.com/opencontainers/runc/security/advisories/GHSA-9493-h29p-rfm2
GitHub Advisory / Wiki ADVISORY
https://github.com/youki-dev/youki/security/advisories/GHSA-4g74-7cff-xcv8
NVD — CVE-2025-62161 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-62161
Security Fix Commit FIX COMMIT
https://github.com/youki-dev/youki/commit/5886c91073b9be748bd8d5aed49c4a820548030a
Youki Source Repository REPOSITORY
https://github.com/youki-dev/youki

Frequently Asked Questions

What is CVE-2025-62161?
CVE-2025-62161 is a security vulnerability in Youki involving youki container escape via "masked path" abuse due to mount race conditions under CWE-363: Race Condition Enabling Link Following.
Which Youki versions are affected?
Affected versions include releases prior to 0.5.7 across affected packages: youki.
What version fixes CVE-2025-62161?
Upgrading to 0.5.7 (or the latest patched release for your respective branch) resolves the vulnerability.
Is youki affected?
Yes, youki is affected in releases prior to 0.5.7. Upgrade your dependency to 0.5.7 or later.
What is the CVSS score of CVE-2025-62161?
CVE-2025-62161 has a CVSS v3.1 base score of 10.0 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.
What CWE is associated with CVE-2025-62161?
CVE-2025-62161 is classified under CWE-363: Race Condition Enabling Link Following (The product checks the status of a file or directory before accessing it, which produces a race condition in which the file can be replaced with a link before the access is performed, causing the product to access the wrong file.).
How can I check crates.io dependencies for CVE-2025-62161?
Run the dependency tree command: 'inspect dependencies for youki'. 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-4g74-7cff-xcv8",
  "modified" : "2025-11-15T02:25:02Z",
  "published" : "2025-11-05T18:44:18Z",
  "aliases" : [ "CVE-2025-62161" ],
  "summary" : "youki container escape via \"masked path\" abuse due to mount race conditions",
  "details" : "### Impact ###\n\nyouki utilizes bind mounting the container's `/dev/null` as a file mask. When performing this operation, the initial validation of the source `/dev/null` was insufficient. Specifically, we initially failed to verify whether `/dev/null` was genuinely present. However, we did perform validation to ensure that the `/dev/null` path existed within the container, including checking for symbolic links. Additionally, there was a vulnerability in the timing between validation and the actual mount operation.\n\nAs a result, by replacing `/dev/null` with a symbolic link, we can bind-mount arbitrary files from the host system.\n\nThis is a different project, but the core logic is similar to the CVE in runc. Issues were identified in runc, and verification was also conducted in youki to confirm the problems.\nhttps://github.com/opencontainers/runc/security/advisories/GHSA-9493-h29p-rfm2\n\n### Credits\n\nThanks to Lei Wang (@ssst0n3 from Huawei) for finding and reporting the original runc's vulnerability (Attack 1), and Li Fubang (@lifubang from acmcoder.com, CIIC) for discovering another attack vector in runc (Attack 2) based on @ssst0n3's initial findings.\n\nAlso, @cyphar helped youki in finding the problem.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "youki"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.5.7"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/opencontainers/runc/security/advisories/GHSA-9493-h29p-rfm2"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/youki-dev/youki/security/advisories/GHSA-4g74-7cff-xcv8"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-62161"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/youki-dev/youki/commit/5886c91073b9be748bd8d5aed49c4a820548030a"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/youki-dev/youki"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-363", "CWE-61" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-11-05T18:44:18Z",
    "nvd_published_at" : "2025-11-06T00:15:36Z"
  }
}