CVE-2026-55421 — Open edX Platform: SSRF in Studio Video Download Endpoint
Open edX Platform enables the authoring and delivery of online learning at any scale. Prior to commit 00b7c3c, the endpoint accepts user-supplied files[].url, performs a server-side fetch using "requests.get(url, allow_redirects=True)". The fetched bytes are then returned inside a ZIP response. This enables SSRF with response exfiltration. Redirect-following is enabled, and there is no timeout in the vulnerable fetch path. This issue has been patched via commit 00b7c3c.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.5% (30-day exploitation probability)+6
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Openedx Openedx-platform).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (ssrf), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Openedx | Openedx-platform | version < 00b7c3ce418b487c5696b064fc5033594b045e75 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 6.8 | CVSS 3.1 | Medium | 2.3 | 4.0 | security-advisories@github.com via NIST National Vulnerability Database |
| 6.8 | CVSS 3.1 | Medium | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N (score shown at the top: security-advisories@github.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Monitor outbound requests from the server to internal IPs and cloud metadata endpoints.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · openedx/openedx-platform
- SSVC assessment updated
- Record published
- CVSS changed · 6.8
- Source status changed · → Deferred
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
4 on the record
- github.com/openedx/openedx-platform/security/advisories/GHSA-fpf9-9rpr-jvrx
- github.com/openedx/openedx-platform/commit/c9831c2c9f53b7aa9a61d80e6d91a9941ce52
- github.com/openedx/openedx-platform/commit/00b7c3ce418b487c5696b064fc5033594b045
- github.com/openedx/openedx-platform/commit/241b914a191ec24658b9cde75a7114db40a5d
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-85271 Open edX Platform: Stored CSS Injection in Email Digest Notifications via Unsanitized Thread Title (incomplete patch of CVE-2026-42857) 27d
- Medium CVE-2026-85272 Open edX Platform: Path traversal via prefix-bypass in safe_extractall Path Validation 27d
- High CVE-2026-53635 Open edX Platform: Insufficient Permission on set_course_mode_price() Sep 2, 2026
- Medium CVE-2026-53636 Open edX LTI OAuth Replay Attack Sep 2, 2026
- Critical CVE-2026-42858 Open edX Platform: Server-Side Request Forgery (SSRF) in SAML Provider Data Sync Endpoint May 11, 2026
- Medium CVE-2026-42857 Open edX Platform: Stored CSS Injection in Email Notifications via Incomplete HTML Sanitization May 11, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-55421 is "Open edX Platform: SSRF in Studio Video Download Endpoint", rated Medium. It affects Openedx-platform (Openedx); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.8 describes technical severity. EPSS 0.46% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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