Missing Authentication for Critical Function in OpenBao - CVE-2026-33757
Published: April 21, 2026
Vulnerability identifier: #VU126696
CSH Severity: High
CVSS v4: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-33757
CWE-ID: CWE-306
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to obtain an OpenBao token associated with the attacker's session by tricking a victim into completing a login flow.
The vulnerability exists due to improper authentication flow control in the JWT/OIDC direct callback mode when handling authentication requests for roles configured with callback_mode set to direct. A remote attacker can start an authentication request and have the victim visit a crafted URL to obtain an OpenBao token associated with the attacker's session by tricking a victim into completing a login flow.
User interaction is required to visit the URL and complete the login flow.
Affected software
OpenBao
Fedora
openbao
Fedora
openbao
How to mitigate CVE-2026-33757
Install security update from vendor's website.
OpenBao - update to 2.5.2
openbao - addressed in versions 2.5.2-1.el8, 2.5.2-1.el9, 2.5.2-1.el10_1, 2.5.2-1.el10_2, 2.5.2-1.el10_3, 2.5.2-1.fc42, 2.5.2-1.fc43, 2.5.2-1.fc44
openbao - addressed in versions 2.5.2-1.el8, 2.5.2-1.el9, 2.5.2-1.el10_1, 2.5.2-1.el10_2, 2.5.2-1.el10_3, 2.5.2-1.fc42, 2.5.2-1.fc43, 2.5.2-1.fc44