Security Digest · Vulnerability record
CVE-2026-33757: OpenBao lacks user confirmation for OIDC direct callback mode
OpenBao is an open source identity-based secrets management system.
CVSS 9.6 Critical EPSS 0.6% · p48
Should you act?
Critical and remotely reachable
No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.6%, percentile 48: FIRST’s model estimates a 0.6% chance of exploitation activity in the next 30 days, higher than 48% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs a user to click or open something. Phishing makes that realistic, but it is not wormable.
- Only applies if your dependency tree includes
github.com/openbao/openbao(Go) < 0.0.0-20260325142553-e32103951925, fixed in 0.0.0-20260325142553-e32103951925. Check your lockfile, including transitive dependencies.
What it is
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 callbackmode 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 callbackmode=direct or enforcing confirmation for every session on the token issuer side for the Client ID used by OpenBao.
From the GitHub advisory
Impact
OpenBao does not prompt for user confirmation when logging in via JWT/OIDC and a role with callbackmode 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.
Patches Version 2.5.2 includes an additional confirmation screen for direct type logins that requires manual user interaction in order to finish the authentication.
Workarounds This issue can be worked around either by removing any roles with callbackmode=direct or enforcing confirmation for every session on the token issuer side for the Client ID used by OpenBao.
Weakness type: CWE-384.
Product: github.com/openbao/openbao (Go) · Assigned by: GitHub_M · Published: 2026-03-27
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| Go | github.com/openbao/openbao | < 0.0.0-20260325142553-e32103951925 | 0.0.0-20260325142553-e32103951925 |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| openbao | openbao | < 2.5.2 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_M | 3.1 | 9.6 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L |
| redhat-SADP | 3.1 | 9.6 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L |
| GitHub | 3.1 | 9.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Privileges required: none (no login)
- User interaction: required (a user must click/open something)
- Scope: changed (can affect other components)
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none, automatable no, technical impact total.
- FIRST EPSS (model of 2026-10-21): 0.61% probability of exploitation activity in the next 30 days; percentile 48.
Timeline
- — GitHub-reviewed advisory GHSA-7q7g-x6vg-xpc3 published (critical)
- — CVE record published by GitHub_M
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vulnerability records
- GitHub Advisory GHSA-7q7g-x6vg-xpc3 github.com
- CVE.org record CVE-2026-33757 cve.org
- NVD entry CVE-2026-33757 nvd.nist.gov
Other references from the CVE record and advisory
- github.com github.com
- github.com github.com
- datatracker.ietf.org datatracker.ietf.org
- access.redhat.com access.redhat.com
- RHBZ#2452269 bugzilla.redhat.com
- security.access.redhat.com security.access.redhat.com