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.
CVE-2026-53636
“—” beside the score: it is equal to the CVSS score beside it.
This medium-severity CVE scores 4.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3% (20th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
Also known asEUVD-2026-70222 (ENISA EUVD)Source: ENISA EUVD
- CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.
- CVSS v3
- 4.7
- EG Score
- 4.7MEDIUMmedium confidence
- EG Risk
- 37EG Risk 37/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity47% × 45%Impact severity (EG Severity): CVSS 4.7 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation40% × 40%EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: No fix is confirmed yet. Check with the vendor for a fixed release; until one is applied, restrict network exposure of the affected system on your normal schedule. - EPSS PROB
- 0.3%
- EPSS %ILE
- 20th
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (4.7): severity, escalated by confirmed exploitation. This CVE's 4.7 is its impact severity (EG Severity), not escalated.
- EG Severity
- 4.7 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
- EG Likelihood
- 0.3% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says. In the directive's words, “Fix on system upgrade” means that, “unless conditions change”, the vulnerability “should be remediated the next time the vulnerable asset receives a scheduled major upgrade or rebuild”: its timelines are “dynamic as facts change”, and a KEV listing shortens them.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
No fix is confirmed yet. Check with the vendor for a fixed release; until one is applied, restrict network exposure of the affected system on your normal schedule.
Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says. In the directive's words, “Fix on system upgrade” means that, “unless conditions change”, the vulnerability “should be remediated the next time the vulnerable asset receives a scheduled major upgrade or rebuild”: its timelines are “dynamic as facts change”, and a KEV listing shortens them.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
September 2, 2026
Last Modified
September 9, 2026
Advisory Details (4)
Auto-updated Sep 2, 2026commit 50af17b05d82 (openedx/openedx-platform)
Fix landed in openedx/openedx-platform commit 50af17b05d82 — awaiting tagged release
https://github.com/openedx/openedx-platform/commit/50af17b05d82a8c7e8e690cc2783a8a0ba330bc3commit 3a5ac856c795 (openedx/openedx-platform)
Fix landed in openedx/openedx-platform commit 3a5ac856c795 — awaiting tagged release
https://github.com/openedx/openedx-platform/commit/3a5ac856c79557c5c74d8b3e6578f289d7cceecdcommit 0a92cf25de88 (openedx/openedx-platform)
Fix landed in openedx/openedx-platform commit 0a92cf25de88 — awaiting tagged release
https://github.com/openedx/openedx-platform/commit/0a92cf25de8844bf840ffd5d18dcfd940031a2baOpen edX LTI OAuth Replay Attack · Advisory · openedx/openedx-platform · GitHub
https://github.com/openedx/openedx-platform/security/advisories/GHSA-6gm5-c49g-p3h9Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 8× in last 7d / 44× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
- 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-10-30 11:55 UTCOSV refresh
- 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-10-25 14:20 UTCEG score recompute
- 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-10-22 21:48 UTCEG score recompute
- 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-10-18 03:31 UTCEG score recompute
- 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.3% · 18th percentile
- 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.3% · 18th percentile
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- 2026-10-12 15:57 UTCEG score recompute
- 2026-10-11 19:40 UTCEG score recompute
- 2026-10-11 16:55 UTCEG score recompute
- 2026-10-11 14:18 UTCEG score recompute
- 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.3% · 18th percentile
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 18th percentile
- 2026-10-10 03:08 UTCEG score recompute
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 18th percentile
- 2026-10-09 01:38 UTCEG score recompute
- 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.3% · 18th percentile
- 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 18th percentile
- 2026-10-07 23:41 UTCEG score recompute
- 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.3% · 18th percentile
- 2026-10-06 11:22 UTCEG score recompute
- 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.3% · 18th percentile
- 2026-10-05 10:04 UTCEG score recompute
- 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.3% · 18th percentile
- 2026-10-04 08:45 UTCEG score recompute
- 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.3% · 18th percentile
- 2026-10-03 07:22 UTCEG score recompute
- 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.3% · 18th percentile
- 2026-10-02 06:04 UTCEG score recompute
- 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.3% · 18th percentile
- 2026-10-01 04:24 UTCEG score recompute
- 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.3% · 18th percentile
- 2026-09-30 03:03 UTCEG score recompute
- 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.3% · 18th percentile
- 2026-09-28 20:54 UTCEG score recompute
- 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.3% · 18th percentile
- 2026-09-27 19:28 UTCEG score recompute
- 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.3% · 18th percentile
- 2026-09-26 18:03 UTCEG score recompute
- 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.3% · 18th percentile
- 2026-09-24 15:25 UTCEG score recompute
- 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.3% · 18th percentile
- 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 7th percentile
- 2026-09-23 14:07 UTCEG score recompute
- 2026-09-22 12:49 UTCEG score recompute
- 2026-09-21 11:31 UTCEG score recompute
- 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 7th percentile
- 2026-09-20 10:13 UTCEG score recompute
- 2026-09-19 08:56 UTCEG score recompute
- 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 7th percentile
- 2026-09-18 07:38 UTCEG score recompute
- 2026-09-17 06:20 UTCEG score recompute
- 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 7th percentile
- 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 6th percentile
- 2026-09-15 03:39 UTCEG score recompute
- 2026-09-14 02:21 UTCEG score recompute
- 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.2% · 6th percentile
- 2026-09-13 01:04 UTCEG score recompute
- 2026-09-11 23:46 UTCEG score recompute
- 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 6th percentile
- 2026-09-10 22:28 UTCEG score recompute
- 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.2% · 6th percentile
- 2026-09-09 03:30 UTCEG score recompute
- 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.2% · 6th percentile
- 2026-09-08 02:12 UTCEG score recompute
- 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.2% · 6th percentile
- 2026-09-07 00:54 UTCEG score recompute
- 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 6th percentile
- 2026-09-05 23:32 UTCEG score recompute
- 2026-09-04 22:14 UTCEG score recompute
- 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.2% · 6th percentile
- 2026-09-02 19:31 UTCEG score recompute
- 2026-09-02 18:31 UTCEG score recompute
- 2026-09-02 17:35 UTCEG score recompute
- 2026-09-02 16:58 UTCEG score recomputeFirst assessed: 4.7 MEDIUM
- 2026-09-02 16:55 UTCMITRE cvelistV5first tracked
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Frequently asked(5)
What is CVE-2026-53636?
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Dependency Blast Radius
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