Vulnerability in Openedx Openedx-Platform

CVE-2026-53636

Open edX Platform enables the authoring and delivery of online learning at any scale. Prior to commit 3a5ac85, a security vulnerability has been identified in the Open edX LMS platform's LTI (Learning Tools Interoperability) Provider implementation. The validate_timestamp_and_nonce function in lms/djangoapps/lti_provider/signature_validator.py does not validate OAuth nonces or timestamps, allowing an attacker who captures a valid LTI launch request to replay it an unlimited number of times without detection. This issue has been patched via commit 3a5ac85.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.7 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (19.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 19th percentile — 19.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-53636: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-53636?
CVE-2026-53636 is a medium-severity vulnerability in Openedx Openedx-Platform, classified under Authentication Bypass by Capture-replay. CVSS score: 4.7/10. Published 2026-09-02.
How severe is CVE-2026-53636?
Medium severity. CVSS v3 base score is 4.7 out of 10.