Attack Chain

1. An attacker authenticates as an administrator to a vulnerable Metabase Enterprise instance.
2. The attacker crafts a malicious serialization archive containing an injected INIT property within the H2 JDBC spec.
3. The malicious archive is submitted to the /api/ee/serialization/import endpoint via a POST request.
4. Metabase processes the archive, triggering the H2 JDBC driver with the injected INIT property.
5. The INIT property executes arbitrary SQL commands during a database synchronization operation.
6. The attacker gains the ability to execute arbitrary code on the server hosting the Metabase instance.
7. The attacker leverages the code execution to read arbitrary files on the system.
8. The attacker may use this access to exfiltrate sensitive data, pivot to other systems, or disrupt services.

Impact

Successful exploitation of CVE-2026-33725 allows attackers to gain complete control over affected Metabase Enterprise instances, potentially leading to data breaches, service disruption, and lateral movement within the network. The vulnerability affects all versions of Metabase Enterprise that have serialization, dating back to at least version 1.47, before being patched in versions 1.54.22, 1.55.22, 1.56.22, 1.57.16, 1.58.10, and 1.59.4. Given the widespread use of Metabase for business intelligence, a successful attack can expose sensitive business data.

Recommendation

• Upgrade Metabase Enterprise instances to versions 1.54.22, 1.55.22, 1.56.22, 1.57.16, 1.58.10, 1.59.4, or later to patch CVE-2026-33725.
• As a temporary workaround, disable the serialization import endpoint in the Metabase instance, as recommended in the overview, to prevent access to the vulnerable code paths.
• Deploy the Sigma rule "Detect Metabase Enterprise Serialization Import Attempt" to monitor for attempts to exploit the vulnerability via the /api/ee/serialization/import endpoint.