CVE-2025-65961: Contao/core bundle Cross-Site Scripting Vulnerability

LOW
Advisory Identifier: GHSA-68q5-78xp-cwwc
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CVSS 3.3
CWE-87 CWE-79
Published
Advisory Summary

CVE-2025-65961 is a LOW (CVSS 3.3) cross-site scripting vulnerability (CWE-87: Improper Neutralization of Alternate XSS Syntax) affecting Contao/core bundle libraries in the Packagist ecosystem. The issue involves contao is vulnerable to cross-site scripting in templates. Remediation is available by upgrading affected packages to version 4.13.57, 5.3.42, 5.6.5.

CVE-2025-65961 at a Glance

CVE Identifier CVE-2025-65961
GHSA Identifier GHSA-68q5-78xp-cwwc
Severity LOW
CVSS v3.1 Base Score 3.3
CWE Classification CWE-87: Improper Neutralization of Alternate XSS Syntax
Affected Product Contao/core bundle
Package Ecosystem Packagist
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:N/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:N).

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

How to Fix CVE-2025-65961

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

contao/core-bundle fixed: 4.13.57 
Upgrade contao/core-bundle to 4.13.57
contao/core-bundle fixed: 5.3.42 
Upgrade contao/core-bundle to 5.3.42
contao/core-bundle fixed: 5.6.5 
Upgrade contao/core-bundle to 5.6.5
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 contao/core-bundle

How to Check if You Are Affected

To determine whether your application is affected by CVE-2025-65961, inspect your project dependencies for Contao/core bundle:

inspect dependencies for contao/core-bundle

Analyze the terminal output to locate any version of Contao/core bundle in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.13.57), 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-87: Improper Neutralization of Alternate XSS Syntax, where the product does not neutralize or incorrectly neutralizes user-controlled input for alternate script syntax. In Contao/core bundle, 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 It is possible to inject code into the template output that will be executed in the browser in the front end and back end. ### Patches Update to Contao 4.13.57, 5.3.42 or 5.6.5. ### Workarounds Do not use the affected templates or patch them manually. ### Refsources https://contao.org/en/security-advisories/cross-site-scripting-in-templates

CVE-2025-65961 Affected Contao/core bundle Versions

3 component(s)
Fixed Versions:
4.13.575.3.425.6.5
Product / Package Ecosystem Affected Versions Fixed Version
contao/core-bundle
 Packagist
≥ 4.0.0
< 4.13.57
4.13.57
contao/core-bundle
 Packagist
≥ 5.0.0-RC1
< 5.3.42
5.3.42
contao/core-bundle
 Packagist
≥ 5.4.0-RC1
< 5.6.5
5.6.5

References

GitHub Advisory / Wiki ADVISORY
https://github.com/contao/contao/security/advisories/GHSA-68q5-78xp-cwwc
NVD — CVE-2025-65961 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-65961
Contao/core bundle Security Information SECURITY
https://contao.org/en/security-advisories/cross-site-scripting-in-templates
Contao/core bundle Source Repository REPOSITORY
https://github.com/contao/contao

Frequently Asked Questions

What is CVE-2025-65961?
CVE-2025-65961 is a security vulnerability in Contao/core bundle involving Contao is vulnerable to cross-site scripting in templates under CWE-87: Improper Neutralization of Alternate XSS Syntax.
Which Contao/core bundle versions are affected?
Affected versions include releases prior to 4.13.57, 5.3.42, 5.6.5 across affected packages: contao/core-bundle.
What version fixes CVE-2025-65961?
Upgrading to 4.13.57, 5.3.42, 5.6.5 (or the latest patched release for your respective branch) resolves the vulnerability.
Is contao/core-bundle affected?
Yes, contao/core-bundle is affected in releases prior to 4.13.57, 5.3.42, 5.6.5. Upgrade your dependency to 4.13.57, 5.3.42, 5.6.5 or later.
What is the CVSS score of CVE-2025-65961?
CVE-2025-65961 has a CVSS v3.1 base score of 3.3 (LOW) with vector string CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:N.
What CWE is associated with CVE-2025-65961?
CVE-2025-65961 is classified under CWE-87: Improper Neutralization of Alternate XSS Syntax (The product does not neutralize or incorrectly neutralizes user-controlled input for alternate script syntax.).
How can I check Packagist dependencies for CVE-2025-65961?
Run the dependency tree command: 'inspect dependencies for contao/core-bundle'. 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-68q5-78xp-cwwc",
  "modified" : "2025-11-27T08:59:34Z",
  "published" : "2025-11-25T20:48:13Z",
  "aliases" : [ "CVE-2025-65961" ],
  "summary" : "Contao is vulnerable to cross-site scripting in templates",
  "details" : "### Impact\n\nIt is possible to inject code into the template output that will be executed in the browser in the front end and back end.\n\n### Patches\n\nUpdate to Contao 4.13.57, 5.3.42 or 5.6.5.\n\n### Workarounds\n\nDo not use the affected templates or patch them manually.\n\n### Refsources\n\nhttps://contao.org/en/security-advisories/cross-site-scripting-in-templates",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "contao/core-bundle"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.0.0"
      }, {
        "fixed" : "4.13.57"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "contao/core-bundle"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "5.0.0-RC1"
      }, {
        "fixed" : "5.3.42"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "contao/core-bundle"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "5.4.0-RC1"
      }, {
        "fixed" : "5.6.5"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/contao/contao/security/advisories/GHSA-68q5-78xp-cwwc"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-65961"
  }, {
    "type" : "WEB",
    "url" : "https://contao.org/en/security-advisories/cross-site-scripting-in-templates"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/contao/contao"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79", "CWE-87" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-11-25T20:48:13Z",
    "nvd_published_at" : "2025-11-25T19:15:51Z"
  }
}