CVE-2026-38991: Cockpit hq/cockpit Cockpit Vulnerable To Unrestricted Upload Vulnerability

HIGH
Advisory Identifier: GHSA-j2rx-4jg9-79mw
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CVSS 8.8
CWE-434
Published
Advisory Summary

CVE-2026-38991 is a HIGH (CVSS 8.8) cockpit vulnerable to unrestricted upload vulnerability (CWE-434: Unrestricted Upload of File with Dangerous Type) affecting Cockpit hq/cockpit libraries in the Packagist ecosystem. The issue involves cockpit vulnerable to unrestricted upload of file with dangerous type. Remediation is available by upgrading affected packages to version 2.14.0.

CVE-2026-38991 at a Glance

CVE Identifier CVE-2026-38991
GHSA Identifier GHSA-j2rx-4jg9-79mw
Severity HIGH
CVSS v3.1 Base Score 8.8
CWE Classification CWE-434: Unrestricted Upload of File with Dangerous Type
Affected Product Cockpit hq/cockpit
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 8.8

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

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

How to Fix CVE-2026-38991

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

cockpit-hq/cockpit fixed: 2.14.0 
Upgrade cockpit-hq/cockpit to 2.14.0
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 cockpit-hq/cockpit

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-38991, inspect your project dependencies for Cockpit hq/cockpit:

inspect dependencies for cockpit-hq/cockpit

Analyze the terminal output to locate any version of Cockpit hq/cockpit in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.14.0), 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-434: Unrestricted Upload of File with Dangerous Type, where the product allows the upload or transfer of dangerous file types that are automatically processed within its environment. In Cockpit hq/cockpit, 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

Cockpit versions 2.13.5 and earlier are affected by a misconfiguration within the Bucket component _isFileTypeAllowed function where a specially crafted filename bypasses an extension filter. This allows an authenticated attacker to rename arbitrary files with the .php file extension enabling arbitrary code to be executed on the underlying server.

CVE-2026-38991 Affected Cockpit hq/cockpit Versions

1 component(s)
Fixed Versions:
2.14.0
Product / Package Ecosystem Affected Versions Fixed Version
cockpit-hq/cockpit
 Packagist
< 2.14.0
2.14.0

References

NVD — CVE-2026-38991 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-38991
felsec.com/posts/cockpit-cms-2... WEB
https://felsec.com/posts/cockpit-cms-2.13.5-multi-vulns
Cockpit hq/cockpit Source Repository REPOSITORY
https://github.com/Cockpit-HQ/Cockpit
Cockpit hq/cockpit Release RELEASE
https://github.com/Cockpit-HQ/Cockpit/releases/tag/2.14.0

Frequently Asked Questions

What is CVE-2026-38991?
CVE-2026-38991 is a security vulnerability in Cockpit hq/cockpit involving Cockpit Vulnerable to Unrestricted Upload of File with Dangerous Type under CWE-434: Unrestricted Upload of File with Dangerous Type.
Which Cockpit hq/cockpit versions are affected?
Affected versions include releases prior to 2.14.0 across affected packages: cockpit-hq/cockpit.
What version fixes CVE-2026-38991?
Upgrading to 2.14.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is cockpit-hq/cockpit affected?
Yes, cockpit-hq/cockpit is affected in releases prior to 2.14.0. Upgrade your dependency to 2.14.0 or later.
What is the CVSS score of CVE-2026-38991?
CVE-2026-38991 has a CVSS v3.1 base score of 8.8 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-38991?
CVE-2026-38991 is classified under CWE-434: Unrestricted Upload of File with Dangerous Type (The product allows the upload or transfer of dangerous file types that are automatically processed within its environment.).
How can I check Packagist dependencies for CVE-2026-38991?
Run the dependency tree command: 'inspect dependencies for cockpit-hq/cockpit'. 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-j2rx-4jg9-79mw",
  "modified" : "2026-05-06T23:11:16Z",
  "published" : "2026-04-29T18:31:34Z",
  "aliases" : [ "CVE-2026-38991" ],
  "summary" : "Cockpit Vulnerable to Unrestricted Upload of File with Dangerous Type",
  "details" : "Cockpit versions 2.13.5 and earlier are affected by a misconfiguration within the Bucket component _isFileTypeAllowed function where a specially crafted filename bypasses an extension filter. This allows an authenticated attacker to rename arbitrary files with the .php file extension enabling arbitrary code to be executed on the underlying server.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "cockpit-hq/cockpit"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.14.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-38991"
  }, {
    "type" : "WEB",
    "url" : "https://felsec.com/posts/cockpit-cms-2.13.5-multi-vulns"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/Cockpit-HQ/Cockpit"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Cockpit-HQ/Cockpit/releases/tag/2.14.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-434" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-06T23:11:16Z",
    "nvd_published_at" : "2026-04-29T16:16:23Z"
  }
}