CVE-2026-6365: Drupal/core Cross-Site Scripting Vulnerability

MODERATE
Advisory Identifier: GHSA-f3cj-mjqm-fhvj
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CVSS 6.1
CWE-79
Published
Advisory Summary

CVE-2026-6365 is a MODERATE (CVSS 6.1) cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Drupal/core libraries in the Packagist ecosystem. The issue involves drupal core is vulnerable to cross-site scripting. Remediation is available by upgrading affected packages to version 10.5.9, 10.6.7, 11.2.11, 11.3.7.

CVE-2026-6365 at a Glance

CVE Identifier CVE-2026-6365
GHSA Identifier GHSA-f3cj-mjqm-fhvj
Severity MODERATE
CVSS v3.1 Base Score 6.1
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Drupal/core
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 6.1

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

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

How to Fix CVE-2026-6365

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

drupal/core fixed: 10.5.9 
Upgrade drupal/core to 10.5.9
drupal/core fixed: 10.6.7 
Upgrade drupal/core to 10.6.7
drupal/core fixed: 11.2.11 
Upgrade drupal/core to 11.2.11
drupal/core fixed: 11.3.7 
Upgrade drupal/core to 11.3.7
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 drupal/core

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-6365, inspect your project dependencies for Drupal/core:

inspect dependencies for drupal/core

Analyze the terminal output to locate any version of Drupal/core in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 10.5.9), 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-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. In Drupal/core, 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

Improper Neutralization of Input During Web Page Generation ("Cross-site Scripting") vulnerability in Drupal Drupal core allows Cross-Site Scripting (XSS). This issue affects Drupal core: from 8.0.0 before 10.5.9, from 10.6.0 before 10.6.7, from 11.0.0 before 11.2.11, from 11.3.0 before 11.3.7.

CVE-2026-6365 Affected Drupal/core Versions

4 component(s)
Fixed Versions:
10.5.910.6.711.2.1111.3.7
Product / Package Ecosystem Affected Versions Fixed Version
drupal/core
 Packagist
≥ 8.0.0
< 10.5.9
10.5.9
drupal/core
 Packagist
≥ 10.6.0
< 10.6.7
10.6.7
drupal/core
 Packagist
≥ 11.0.0
< 11.2.11
11.2.11
drupal/core
 Packagist
≥ 11.3.0
< 11.3.7
11.3.7

References

NVD — CVE-2026-6365 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-6365
Drupal/core Source Repository REPOSITORY
https://github.com/drupal/core
www.drupal.org/sa-core-2026-001 WEB
https://www.drupal.org/sa-core-2026-001

Frequently Asked Questions

What is CVE-2026-6365?
CVE-2026-6365 is a security vulnerability in Drupal/core involving Drupal core is Vulnerable to Cross-Site Scripting under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Drupal/core versions are affected?
Affected versions include releases prior to 10.5.9, 10.6.7, 11.2.11, 11.3.7 across affected packages: drupal/core.
What version fixes CVE-2026-6365?
Upgrading to 10.5.9, 10.6.7, 11.2.11, 11.3.7 (or the latest patched release for your respective branch) resolves the vulnerability.
Is drupal/core affected?
Yes, drupal/core is affected in releases prior to 10.5.9, 10.6.7, 11.2.11, 11.3.7. Upgrade your dependency to 10.5.9, 10.6.7, 11.2.11, 11.3.7 or later.
What is the CVSS score of CVE-2026-6365?
CVE-2026-6365 has a CVSS v3.1 base score of 6.1 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
What CWE is associated with CVE-2026-6365?
CVE-2026-6365 is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.).
How can I check Packagist dependencies for CVE-2026-6365?
Run the dependency tree command: 'inspect dependencies for drupal/core'. 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-f3cj-mjqm-fhvj",
  "modified" : "2026-06-05T18:26:33Z",
  "published" : "2026-05-20T00:31:42Z",
  "aliases" : [ "CVE-2026-6365" ],
  "summary" : "Drupal core is Vulnerable to Cross-Site Scripting",
  "details" : "Improper Neutralization of Input During Web Page Generation (\"Cross-site Scripting\") vulnerability in Drupal Drupal core allows Cross-Site Scripting (XSS).\n\nThis issue affects Drupal core: from 8.0.0 before 10.5.9, from 10.6.0 before 10.6.7, from 11.0.0 before 11.2.11, from 11.3.0 before 11.3.7.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "drupal/core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "8.0.0"
      }, {
        "fixed" : "10.5.9"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "drupal/core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.6.0"
      }, {
        "fixed" : "10.6.7"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "drupal/core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "11.0.0"
      }, {
        "fixed" : "11.2.11"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "drupal/core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "11.3.0"
      }, {
        "fixed" : "11.3.7"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-6365"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/drupal/core"
  }, {
    "type" : "WEB",
    "url" : "https://www.drupal.org/sa-core-2026-001"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-05T18:26:33Z",
    "nvd_published_at" : "2026-05-19T23:16:58Z"
  }
}