CVE-2025-3643: Moodle/moodle Cross-Site Scripting Vulnerability

MODERATE
Advisory Identifier: GHSA-hxgg-4qww-85ph
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CVSS 5.4
CWE-79
Published
Advisory Summary

CVE-2025-3643 is a MODERATE (CVSS 5.4) cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Moodle/moodle libraries in the Packagist ecosystem. The issue involves moodle has reflected cross-site scripting risk in policy tool. Remediation is available by upgrading affected packages to version 4.1.18, 4.3.12, 4.4.8, 4.5.4.

CVE-2025-3643 at a Glance

CVE Identifier CVE-2025-3643
GHSA Identifier GHSA-hxgg-4qww-85ph
Severity MODERATE
CVSS v3.1 Base Score 5.4
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Moodle/moodle
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 5.4

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

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
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-2025-3643

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

moodle/moodle fixed: 4.1.18 
Upgrade moodle/moodle to 4.1.18
moodle/moodle fixed: 4.3.12 
Upgrade moodle/moodle to 4.3.12
moodle/moodle fixed: 4.4.8 
Upgrade moodle/moodle to 4.4.8
moodle/moodle fixed: 4.5.4 
Upgrade moodle/moodle to 4.5.4
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 moodle/moodle

How to Check if You Are Affected

To determine whether your application is affected by CVE-2025-3643, inspect your project dependencies for Moodle/moodle:

inspect dependencies for moodle/moodle

Analyze the terminal output to locate any version of Moodle/moodle in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.1.18), 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 Moodle/moodle, 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

A flaw was found in Moodle. The return URL in the policy tool required additional sanitizing to prevent a reflected Cross-site scripting (XSS) risk.

CVE-2025-3643 Affected Moodle/moodle Versions

4 component(s)
Fixed Versions:
4.1.184.3.124.4.84.5.4
Product / Package Ecosystem Affected Versions Fixed Version
moodle/moodle
 Packagist
< 4.1.18
4.1.18
moodle/moodle
 Packagist
≥ 4.3.0-beta
< 4.3.12
4.3.12
moodle/moodle
 Packagist
≥ 4.4.0-beta
< 4.4.8
4.4.8
moodle/moodle
 Packagist
≥ 4.5.0-beta
< 4.5.4
4.5.4

References

NVD — CVE-2025-3643 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-3643
Security Fix Commit FIX COMMIT
https://github.com/moodle/moodle/commit/ff9bbd6d9e7d6267ce85e6c9afbeb19581f2a85f
Moodle/moodle Security Information SECURITY
https://access.redhat.com/security/cve/CVE-2025-3643
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=2359742
Moodle/moodle Source Repository REPOSITORY
https://github.com/moodle/moodle
moodle.org/mod/forum/discuss.p... WEB
https://moodle.org/mod/forum/discuss.php?d=467604

Frequently Asked Questions

What is CVE-2025-3643?
CVE-2025-3643 is a security vulnerability in Moodle/moodle involving Moodle has reflected Cross-site Scripting risk in policy tool under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Moodle/moodle versions are affected?
Affected versions include releases prior to 4.1.18, 4.3.12, 4.4.8, 4.5.4 across affected packages: moodle/moodle.
What version fixes CVE-2025-3643?
Upgrading to 4.1.18, 4.3.12, 4.4.8, 4.5.4 (or the latest patched release for your respective branch) resolves the vulnerability.
Is moodle/moodle affected?
Yes, moodle/moodle is affected in releases prior to 4.1.18, 4.3.12, 4.4.8, 4.5.4. Upgrade your dependency to 4.1.18, 4.3.12, 4.4.8, 4.5.4 or later.
What is the CVSS score of CVE-2025-3643?
CVE-2025-3643 has a CVSS v3.1 base score of 5.4 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.
What CWE is associated with CVE-2025-3643?
CVE-2025-3643 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-2025-3643?
Run the dependency tree command: 'inspect dependencies for moodle/moodle'. 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-hxgg-4qww-85ph",
  "modified" : "2025-05-08T17:14:50Z",
  "published" : "2025-04-25T15:31:23Z",
  "aliases" : [ "CVE-2025-3643" ],
  "summary" : "Moodle has reflected Cross-site Scripting risk in policy tool",
  "details" : "A flaw was found in Moodle. The return URL in the policy tool required additional sanitizing to prevent a reflected Cross-site scripting (XSS) risk.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "moodle/moodle"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "4.1.18"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "moodle/moodle"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.3.0-beta"
      }, {
        "fixed" : "4.3.12"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "moodle/moodle"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.4.0-beta"
      }, {
        "fixed" : "4.4.8"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "moodle/moodle"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.5.0-beta"
      }, {
        "fixed" : "4.5.4"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-3643"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/moodle/moodle/commit/ff9bbd6d9e7d6267ce85e6c9afbeb19581f2a85f"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/security/cve/CVE-2025-3643"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2359742"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/moodle/moodle"
  }, {
    "type" : "WEB",
    "url" : "https://moodle.org/mod/forum/discuss.php?d=467604"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-04-25T17:28:11Z",
    "nvd_published_at" : "2025-04-25T15:15:38Z"
  }
}