CVE-2025-26528Network attack vector

Stored script execution via unsanitized drop-zone labels

Published Feb 24, 2025 · Updated Feb 24, 2025

Stored XSS in Moodle LMS affected releases allows remote attackers to execute script in another user's browser via a crafted drop-zone label. The question editor accepted droplabel as PARAM_RAW, and the renderer passed the stored label to client code without first applying format_string sanitization. Exploitation requires a victim to load content containing the label; the resulting script runs in that user's browser context without interrupting the server.

CVSS severity6.1
Medium
EPSS probability0.28%
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 affected releases allows remote attackers to execute script in another user's browser via a crafted drop-zone label. The question editor accepted droplabel as PARAM_RAW, and the renderer passed the stored label to client code without first applying format_string sanitization. Exploitation requires a victim to load content containing the label; the resulting script runs in that user's browser context without interrupting the server.

The record

CVE
CVE-2025-26528
Published
Feb 24, 2025
Updated
Feb 24, 2025
Vendor
Moodle
Product
Moodle LMS
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 24, 2025CVE publishedPublication date reported by the CVE source.
  2. Feb 24, 2025Record 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=4.1.0 <4.1.16
  2. Affected versionversion=4.3.0 <4.3.10
  3. Affected versionversion=4.4.0 <4.4.6
  4. Affected versionversion=4.5.0 <4.5.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Moodle · Moodle LMSversion=4.1.0 <4.1.16; version=4.3.0 <4.3.10; version=4.4.0 <4.4.6; version=4.5.0 <4.5.2

Published CVSS scores

3.4Fedora ProjectCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:L/A:N
6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007JavaScript/JScript

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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