CVE-2023-5544Network attack vector

Stored XSS and IDOR via unsafe comment editing

Published Nov 9, 2023 · Updated Aug 2, 2024

Stored XSS in Moodle LMS wiki comments allows remote authenticated users to execute script in another user's browser. The edit_comment_form path loaded raw comment content into a trusted HTML editor, while editcomments.php accepted a comment ID without verifying ownership. Wiki comment access is required, and script execution depends on another user opening the affected comment content.

CVSS severity5.4
Medium
EPSS probability0.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Moodle LMS wiki comments allows remote authenticated users to execute script in another user's browser. The edit_comment_form path loaded raw comment content into a trusted HTML editor, while editcomments.php accepted a comment ID without verifying ownership. Wiki comment access is required, and script execution depends on another user opening the affected comment content.

The record

CVE
CVE-2023-5544
Published
Nov 9, 2023
Updated
Aug 2, 2024
Vendor
Moodle
Product
Moodle LMS
Classifications
CWE-639, CWE-79, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 9, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <3.9.24
  2. Affected versionversion=3.11.0 <3.11.17
  3. Affected versionversion=4.0.0 <4.0.11
  4. Affected versionversion=4.1.0 <4.1.6
  5. Affected versionversion=4.2.0 <4.2.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Moodle · Moodle LMSversion=0 <3.9.24; version=3.11.0 <3.11.17; version=4.0.0 <4.0.11; version=4.1.0 <4.1.6; version=4.2.0 <4.2.3

Published CVSS scores

5.4GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
6.5UbuntuCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-639Authorization Bypass Through User-Controlled Key
CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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