Cyber Resilience

CVE-2025-67855

XSS in Moodle ≤ 4.1.22

Published
03 February 2026
Modified
11 February 2026
CVSS Score v3.1 5.4
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
EPSS Score 0.0033 26th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2025-67855 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Moodle Moodle. Its CVSS base score is 5.4 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Browser Session Hijacking (T1185); ranked at the 26th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SI-15 (Information Output Filtering) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A flaw was found in mooodle. A remote attacker could exploit a reflected Cross-Site Scripting (XSS) vulnerability in the policy tool return URL. This vulnerability arises from insufficient sanitization of URL parameters, allowing attackers to inject malicious scripts through specially…

more

crafted links. Successful exploitation could lead to information disclosure or arbitrary client-side script execution within the user's browser.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1185 Browser Session Hijacking Collection
Adversaries may take advantage of security vulnerabilities and inherent functionality in browser software to change content, modify user-behaviors, and intercept information as part of various browser session hijacking techniques.
T1539 Steal Web Session Cookie Credential Access
An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials.
Why these techniques?

Reflected XSS directly enables browser session hijacking and web session cookie theft via injected scripts.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2023-28331Same product: Moodle Moodle
CVE-2023-5541Same product: Moodle Moodle
CVE-2023-46858Same product: Moodle Moodle
CVE-2023-23921Same product: Moodle Moodle
CVE-2023-23922Same product: Moodle Moodle
CVE-2023-28332Same product: Moodle Moodle
CVE-2023-35131Same product: Moodle Moodle
CVE-2023-5546Same product: Moodle Moodle
CVE-2023-5547Same product: Moodle Moodle
CVE-2023-27293Shared CWE-79

Affected Assets

moodle
moodle
5.1.0 · ≤ 4.1.22 · 4.4.0 — 4.4.11 · 4.5.0 — 4.5.8

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-10 Information Input Validation
  • SI-15 Information Output Filtering
  • SI-3 Malicious Code Protection
Detect
Catch it (NIST detect / respond)
  • SI-3 Malicious Code Protection
Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.1.2
  • V1.3.2

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires validation and sanitization of URL parameters to block malicious script injection in the reflected XSS vector.

prevent

Requires filtering of information returned in URLs/responses to neutralize injected scripts before they reach the browser.

preventdetect

Can enforce web-layer malicious code protections (e.g., WAF rules) that detect and block reflected XSS payloads in HTTP parameters.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly target introduction of XSS via coding standards/testing (mostly), yet the single broad outcome leaves many specific neutralization vectors unaddressed (partial).

PR.PS-02 partial match
prevents

Patching and EOL replacement can remediate known XSS instances in libraries or frameworks (partial) but do nothing to enforce input neutralization in application code (none).

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Secure-coding testing and automated code-analysis tools are applied to detect improper neutralization of script-related content during web-page generation.

prevents

Knowledge exchange on emerging attack techniques and patches reduces the likelihood that cross-site scripting flaws remain unaddressed in deployed applications.

prevents

Operational indicators of compromise for web-application attacks can be incorporated into WAF or input-filtering rules, lowering the likelihood that unsanitized data reaches the browser.

prevents

Requiring language-specific secure-coding standards and automated scanning during the SDLC catches missing output encoding or improper neutralization of untrusted data before the software reaches production.

prevents

Secure-coding standards, SAST scans and removal of insecure code samples together eliminate the failure to neutralize script content that produces cross-site scripting flaws.

none

Webpage malware scanning and block-listing of known malicious sites reduce the likelihood that reflected or stored script payloads reach a user’s browser.

References