CVE-2025-67850
Published: 03 February 2026
Summary
CVE-2025-67850 is a high-severity Cross-site Scripting (CWE-79) vulnerability in Moodle Moodle. Its CVSS base score is 7.3 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 1.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-15 (Information Output Filtering).
Deeper analysis
CVE-2025-67850 is a Cross-Site Scripting (XSS) vulnerability, classified under CWE-79, affecting Moodle. The flaw arises from insufficient validation of user-provided data in the formula editor's arithmetic expression fields, allowing malicious code injection. Published on 2026-02-03, it carries a CVSS v3.1 base score of 7.3 (AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N).
A remote attacker with low privileges (PR:L) can exploit this vulnerability over the network with low complexity by injecting malicious scripts into the arithmetic expression fields. When other users view these expressions, the injected code executes in their web browsers, potentially compromising confidential data or enabling unauthorized actions, though it requires user interaction (UI:R) and does not impact availability.
Mitigation details are available in the referenced advisories, including the Red Hat security page at https://access.redhat.com/security/cve/CVE-2025-67850 and the Bugzilla tracker at https://bugzilla.redhat.com/show_bug.cgi?id=2423838.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-206736
Vulnerability details
A flaw was found in moodle. This vulnerability, known as Cross-Site Scripting (XSS), occurs due to insufficient checks on user-provided data in the formula editor's arithmetic expression fields. A remote attacker could inject malicious code into these fields. When other…
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users view these expressions, the malicious code would execute in their web browsers, potentially compromising their data or leading to unauthorized actions.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
XSS in public-facing Moodle web app directly enables T1190 exploitation and JS injection/execution via T1059.007.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly requires validation of user-supplied arithmetic expressions to reject or sanitize script content before storage or rendering.
Requires filtering of formula-editor output to remove or encode script payloads before they reach other users' browsers.
Restricts or inspects mobile code (JavaScript) introduced via user-controlled formula fields to block execution in viewers' sessions.