CVE-2026-42858

High
8.5
0.05.010.0
Year
2026
Published
May 11, 2026
Known Affected Devices
0
CVSS Score
8.5

What is CVE-2026-42858?

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.

CVSS Vector Breakdown

CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N
AV
Attack Vector
Network

Exploitable remotely over the network without requiring access to the local system.

AC
Attack Complexity
Low

No special conditions required. Exploit can be performed reliably and repeatedly.

PR
Privileges Required
Low

Basic user account required (e.g. standard login without admin rights).

UI
User Interaction
None

No user interaction required. Exploit runs without any victim action.

S
Scope
Changed

Exploiting the vulnerability can affect other components beyond the vulnerable one.

C
Confidentiality Impact
High

Complete loss of confidentiality. All data on the component may be exposed.

I
Integrity Impact
Low

Attacker can modify some data, but scope or consequence is limited.

A
Availability Impact
None

No availability impact. Service remains fully operational.

FAQ

How severe is CVE-2026-42858?

CVE-2026-42858 has a CVSS score of 8.5/10, rated as High. This is a high severity vulnerability and should be patched as soon as possible.

What does the CVSS score mean for CVE-2026-42858?

CVSS (Common Vulnerability Scoring System) rates vulnerability severity from 0.0 to 10.0. CVE-2026-42858 scores 8.5/10 (High). Scores 9.0–10.0 are Critical, 7.0–8.9 are High, 4.0–6.9 are Medium, and below 4.0 are Low.

Which devices are affected by CVE-2026-42858?

The list of devices confirmed to be affected by CVE-2026-42858 is shown in the "Affected Devices" section above. Check your firmware version against the vendor security advisory and apply the latest patch.

How do I fix or mitigate CVE-2026-42858?

Apply the latest firmware or software update from the vendor. Check the References section above for official advisories and patch notes. If no patch is available, consider disabling the affected feature or isolating the device from untrusted networks.