CVE-2026-33757 is a critical-severity (CVSS 9.6) CWE-384 vulnerability in github.com/openbao/openbao. A fix is available for github.com/openbao/openbao — see the affected versions and patch details below.
OpenBao lacks user confirmation for OIDC direct callback mode
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-33757.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
github.com/openbao/openbaoReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/openbao/openbao | all versions | 0.0.0-20260325142553-e32103951925go get github.com/openbao/openbao@v0.0.0-20260325142553-e32103951925 |
Affected Products
openbaoopenbaoDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/openbao/openbao, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/openbao/openbao to 0.0.0-20260325142553-e32103951925 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33757 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
To exploit this vulnerability, an attacker needs to convince a user to visit a crafted URL, limiting the exposure of this flaw. Due to this reason, this issue has been rated with an important severity.
To mitigate this vulnerability, review JWT/OIDC authentication configurations and remove or disable any roles that have 'callback_mode=direct', or enforce a manual confirmation prompt for every session specifically for the Client ID used by OpenBao.Source: Red Hat security advisory for CVE-2026-33757 (CC BY 4.0)
Frequently Asked Questions
Is CVE-2026-33757 in your dependencies?
Find it across Go, including transitive dependencies.