CVE-2026-33758criticalCWE-116CWE-20CWE-79

CVE-2026-33758: critical vulnerability in openbao

OpenBao has Reflected XSS in its OIDC authentication error message

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28Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 9.4epss 0.3%
OpenBao is an open source identity-based secrets management system. Prior to version 2.5.2, OpenBao installations that have an OIDC/JWT authentication method enabled and a role with `callback_mode=direct` configured are vulnerable to XSS via the `error_description` parameter on the page for a failed authentication. This allows an attacker access to the token used in the Web UI by a victim. The `error_description` parameter has been replaced with a static error message in v2.5.2. The vulnerability can be mitigated by removing any roles with `callback_mode` set to `direct`.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
Affected products
openbao · openbao
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