Cross-site scripting in OpenBao - CVE-2026-33758
Published: April 21, 2026
Vulnerability identifier: #VU126697
CSH Severity: Medium
CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
CVE-ID: CVE-2026-33758
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to cross-site scripting in the OIDC authentication error message page when handling the error_description parameter for a failed authentication. A remote attacker can supply a crafted error_description parameter to disclose sensitive information.
Only installations with an OIDC/JWT authentication method enabled and a role configured with callback_mode=direct are vulnerable. User interaction is required.
Affected software
OpenBao
Fedora
openbao
Fedora
openbao
How to mitigate CVE-2026-33758
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