OpenBao lacks user confirmation for OIDC direct callback mode (CVE-2026-33757) | HOL Guard CVE

Critical · CVSS 9.6CVE-2026-33757

OpenBao lacks user confirmation for OIDC direct callback mode

Answer in brief

CVE-2026-33757 records a Critical severity (CVSS 9.6) vulnerability in OpenBao lacks user confirmation for OIDC direct callback mode. The current sources do not mark it as known exploited. The current feed maps openbao/openbao (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Mar 27, 2026Updated Jul 15, 2026Source checked Sep 19, 2026First seen by HOL Jul 15, 2026Material review Jul 15, 2026

Upstream Advisory

Key facts

Risk: Critical · CVSS 9.6
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

CVSS is 9.6. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps openbao/openbao (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
openbao/openbaogeneric	< 2.5.2	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for openbao/openbao.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Mar 27, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Jul 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Jul 15, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.