Auth bypass in Moodle Project
CVE-2026-119555
Moodle 4.2.0 through 4.5.15, 5.0.0 through 5.0.11, 5.1.0 through 5.1.8, 5.2.0 through 5.2.4, and 5.3.0 contain an information disclosure vulnerability in the core_grades_get_feedback web service. The service lacks group-membership and enrolment checks, so non-editing teachers can iterate userid values to read other groups' grade feedback and users' names and identity fields such as email.
Vulnerability class: IDOR (Insecure Direct Object Reference)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Moodle Project — versions 5.3.0
Weakness classification (CWE)
References
- github.com/moodle/moodle/blob/v5.3.0/public/grade/classes/external/get_feedback… (technical-description)
- abraxaslabs.tech/research/moodle-grades-feedback-idor (third-party-advisory)
- github.com/moodle/moodle (product)
- www.vulncheck.com/advisories/moodle-through-5.3.0-5.2.4-5.1.8-5.0.11-and-4.5.15… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-119555?
- CVE-2026-119555 is a medium-severity vulnerability in Moodle Project, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 4.3/10. Published 2026-10-30.
- How severe is CVE-2026-119555?
- Medium severity. CVSS v3 base score is 4.3 out of 10.