CVE-2026-33757

CRITICAL

OpenBao lacks user confirmation for OIDC direct callback mode

Title source: cna
STIX 2.1

Description

OpenBao is an open source identity-based secrets management system. Prior to version 2.5.2, OpenBao does not prompt for user confirmation when logging in via JWT/OIDC and a role with `callback_mode` set to `direct`. This allows an attacker to start an authentication request and perform "remote phishing" by having the victim visit the URL and automatically log-in to the session of the attacker. Despite being based on the authorization code flow, the `direct` mode calls back directly to the API and allows an attacker to poll for an OpenBao token until it is issued. Version 2.5.2 includes an additional confirmation screen for `direct` type logins that requires manual user interaction in order to finish the authentication. This issue can be worked around either by removing any roles with `callback_mode=direct` or enforcing confirmation for every session on the token issuer side for the Client ID used by OpenBao.

Scores

CVSS v3 9.6
EPSS 0.0003
EPSS Percentile 10.1%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-384
Status published
Products (2)
openbao/openbao < 2.5.2 (2 CPE variants)
openbao/openbao 0 - 0.0.0-20260325142553-e32103951925Go
Published Mar 27, 2026
Tracked Since Mar 29, 2026