CVE-2026-128049: CVE-2026-128049: OpenMage Magento LTS before 20.18.2 and 21.0.0-beta1 before 21.0.0-beta3 contains a cross-…

CVE-2026-128049 at a glance

CVE-2026-128049 is a critical-severity CSRF vulnerability in OpenMage Magento LTS, with a CVSS 4.0 base score of 9.4. NVD published it on 2026-11-13 and classifies the weakness as CWE-352. FIRST EPSS puts the probability of exploitation activity in the next 30 days at 0.16% (percentile 5.4, scored 2026-11-14). NVD does not list a fixed version, so the vendor advisory is the reference for the fix. CVERadar maps 1 MITRE ATT&CK technique across Execution, inferred from the CWE and the description. Its CVERadar threat level is 47/100.

What it is

OpenMage Magento LTS before 20.18.2 and 21.0.0-beta1 before 21.0.0-beta3 contains a cross-site request forgery vulnerability in the admin and storefront OAuth confirm and confirmSimple actions, which accept GET requests without form-key validation. Attackers holding OAuth consumer credentials can lure a logged-in administrator or customer to a crafted confirm URL that authorizes the attacker's request token, then exchange it at /oauth/token for a persistent REST API access token bound to the victim.

Patches, mitigations and detection

Fixed versions

NVD does not list a fixed version for this CVE. Use the vendor advisory below.

Derived from the NVD CPE configuration (versionEndExcluding / versionEndIncluding). Always confirm with the vendor advisory.

Vendor advisories and patches

No vendor-tagged reference yet; see the full reference list.

MITRE ATT&CK mitigations for this chain

• M1031 Network Intrusion Prevention (for T1204.001) : If a link is being visited by a user, network intrusion prevention systems and systems designed to scan and remove malicious downloads can be used to block activity.
• M1017 User Training (for T1204.001) : Use user training as a way to bring awareness to common phishing and spearphishing techniques and how to raise suspicion for potentially malicious events.
• M1021 Restrict Web-Based Content (for T1204.001) : If a link is being visited by a user, block unknown or unused files in transit by default that should not be downloaded or by policy from suspicious sites as a best practice to prevent some vectors, such as .scr, .exe, .pif, .cpl, etc. Some download scanning devices can open and analyze compressed and encrypted formats

Detection Generic guidance

• Execution: Watch for the service process spawning shells or script interpreters (cmd.exe, powershell, sh, bash, python) via EDR process-tree rules.

Response checklist Generic guidance

1. Inventory: find every instance of the affected product and version (include internet-facing and forgotten ones).
2. Patch or mitigate per the vendor advisory; if you cannot patch, remove internet exposure or apply the vendor workaround.
3. Assume compromise if the system was exposed before patching: hunt for the indicators in the advisory and review logs back to the disclosure date.
4. Rotate credentials and secrets stored on or used by the affected system if compromise cannot be ruled out.

Before patching, it helps to know every exposed instance; external attack surface monitoring from LayerLogix does that inventory.