CVE-2026-33758: Openbao

Medium severity, CVSS 6.1. EPSS: 0.4% chance of exploitation in the next 30 days.

OpenBao is an open source identity-based secrets management system. Prior to version 2.5.2, OpenBao installations that have an OIDC/JWT authentication method enabled and a role with `callback_mode=direct` configured are vulnerable to XSS via the `error_description` parameter on the page for a failed authentication. This allows an attacker access to the token used in the Web UI by a victim. The `error_description` parameter has been replaced with a static error message in v2.5.2. The vulnerability can be mitigated by removing any roles with `callback_mode` set to `direct`.

Affected products

• Openbao Openbao: before 2.5.2 (fixed in 2.5.2)

Published 2026-03-27. Last modified 2026-07-15.