Quick answer
Direct answer
Risk scores
| CVSS metric | What it means |
|---|---|
| Attack vector (AV:N) | Network: reachable remotely |
| Attack complexity (AC:L) | Low complexity |
| Privileges required (PR:L) | Low privileges required |
| User interaction (UI:N) | No user interaction |
| Scope (S:C) | Scope changed: impact spreads beyond the component |
| Confidentiality (C:H) | High confidentiality impact |
| Integrity (I:L) | Low integrity impact |
| Availability (A:N) | No availability impact |
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N
About Openedx
CVE-2026-42858 affects Openedx, a product from Openedx. Before acting, confirm where Openedx runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.
What the flaw is
In plain terms: Open edX Platform enables the authoring and delivery of online learning at any scale. The sync_provider_data endpoint in SAMLProviderDataViewSet allows authenticated Enterprise Admin users to supply an arbitrary URL via the metadata_url POST parameter. This URL is passed directly to requests.get() in fetch_metadata_xml() without any URL validation, IP filtering, or scheme enforcement. An attacker with Enterprise Admin privileges can force the server to make HTTP requests to internal network services, cloud metadata endpoints (e.g., AWS 169.254.169.254), or other attacker-controlled destinations. This vulnerability is fixed by commit 6fda1f120ff5a590d120ae1180185525f399c6d0 and 70a56246dd9c9df57c596e64bdd8a11b1d9da054.
The weakness class is Server Side Request Forgery. The server can be made to send requests to internal or arbitrary systems.
Based on its CVSS vector, the flaw can be reached over the network, needs some level of access, and needs no user interaction. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Affected versions and timeline
| Field | Detail |
|---|---|
| Product | Openedx |
| Affected versions | Openedx before 2026-04-24 |
| Published | May 11, 2026 |
| Last modified | Jun 17, 2026 |
| Added to CISA KEV | Not listed |
| Assigning CNA | security-advisories@github.com |
How to detect it
- Inventory every instance of Openedx and record the running version against the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
- Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.
How to fix it
- Apply the fixed version of Openedx named in the vendor advisory.
- If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
- Rescan after the change to prove the exposure is gone, then close the ticket.
CTEM action plan
| CTEM stage | What to do for this CVE |
|---|---|
| Scope | Add every business service that depends on Openedx to the current CTEM cycle. |
| Discover | Find all instances, including shadow and cloud deployments, and record versions and exposure. |
| Prioritize | Rank using EPSS and CVSS together with asset exposure and business impact. |
| Validate | Confirm the flaw is reachable and exploitable in your environment and that compensating controls work. |
| Mobilize | Assign the fix to the asset owner with a due date matched to the priority, then verify closure. |
CWE References
- CWE-918: Server Side Request Forgery More CVEs with this weakness
Technical References
Frequently asked questions
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