{"id":"CVE-2026-53636","state":"PUBLISHED","title":"Open edX LTI OAuth Replay Attack","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.","publishedAt":"2026-09-02T16:54:10.403Z","updatedAt":"2026-09-02T18:03:41.926Z","severity":{"score":4.7,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["openedx openedx-platform"],"affected":[{"vendor":"openedx","product":"openedx-platform","versions":[{"version":"< 3a5ac856c79557c5c74d8b3e6578f289d7cceecd","status":"affected"}]}],"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"],"weaknesses":["CWE-294"],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/53xxx/CVE-2026-53636.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53636","state":"PUBLISHED","datePublished":"2026-09-02T16:54:10.403Z","dateUpdated":"2026-09-02T18:03:41.926Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-09T20:16:59.647Z"},"containers":{"cna":{"title":"Open edX LTI OAuth Replay Attack","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"openedx","product":"openedx-platform","versions":[{"version":"< 3a5ac856c79557c5c74d8b3e6578f289d7cceecd","status":"affected"}]}],"references":[{"url":"https://github.com/openedx/openedx-platform/security/advisories/GHSA-6gm5-c49g-p3h9","name":"https://github.com/openedx/openedx-platform/security/advisories/GHSA-6gm5-c49g-p3h9","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/openedx/openedx-platform/commit/0a92cf25de8844bf840ffd5d18dcfd940031a2ba","name":"https://github.com/openedx/openedx-platform/commit/0a92cf25de8844bf840ffd5d18dcfd940031a2ba","tags":["x_refsource_MISC"]},{"url":"https://github.com/openedx/openedx-platform/commit/3a5ac856c79557c5c74d8b3e6578f289d7cceecd","name":"https://github.com/openedx/openedx-platform/commit/3a5ac856c79557c5c74d8b3e6578f289d7cceecd","tags":["x_refsource_MISC"]},{"url":"https://github.com/openedx/openedx-platform/commit/50af17b05d82a8c7e8e690cc2783a8a0ba330bc3","name":"https://github.com/openedx/openedx-platform/commit/50af17b05d82a8c7e8e690cc2783a8a0ba330bc3","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":4.7,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-294","lang":"en","description":"CWE-294: Authentication Bypass by Capture-replay","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-02T16:54:10.403Z"},"source":{"advisory":"GHSA-6gm5-c49g-p3h9","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/openedx/openedx-platform/security/advisories/GHSA-6gm5-c49g-p3h9","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-02T18:03:21.512059Z","id":"CVE-2026-53636","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-02T18:03:41.926Z"}}]}}}