CVE-2026-53636
Open edX LTI OAuth Replay Attack
- State
- Published
- Severity
- 4.7 Medium
- Published
- Sep 2, 2026
- Updated
- Sep 2, 2026
- Reserved
- Jun 9, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 4.7 Medium | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N | GitHub_M |
Weaknesses
- CWE-294 Authentication Bypass by Capture-replay
Affected Products
| Product | Versions |
|---|---|
openedx-platformopenedx |
|
References
- https://github.com/openedx/openedx-platform/security/advisories/GHSA-6gm5-c49g-p3h9
- https://github.com/openedx/openedx-platform/commit/0a92cf25de8844bf840ffd5d18dcfd940031a2ba
- https://github.com/openedx/openedx-platform/commit/3a5ac856c79557c5c74d8b3e6578f289d7cceecd
- https://github.com/openedx/openedx-platform/commit/50af17b05d82a8c7e8e690cc2783a8a0ba330bc3
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