OpenBao has Reflected XSS in its OIDC authentication error message
### Impact 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. ### Patches The `error_description` parameter has been replaced with a static error message in v2.5.2 ### Workarounds The vulnerability can be mitigated by removing any roles with `callback_mode` set to `direct`.
02 / AFFECTED SOFTWARE
Affected packages
131 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
### Impact 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. ### Patches The `error_description` parameter has been replaced with a static error message in v2.5.2 ### Workarounds The vulnerability can be mitigated by removing any roles with `callback_mode` set to `direct`.
OpenBao has Reflected XSS in its OIDC authentication error message in github.com/openbao/openbao
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`.
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`.
05 / REFERENCES
Further evidence
- https://github.com/openbao/openbao
- https://github.com/openbao/openbao/commit/6e2b2dd84f0e47cebc90d6e79609dd5274732662
- https://github.com/openbao/openbao/pull/2709
- https://github.com/openbao/openbao/releases/tag/v2.5.2
- https://github.com/openbao/openbao/security/advisories/GHSA-cpj3-3r2f-xj59
- https://nvd.nist.gov/vuln/detail/CVE-2026-33758
- https://access.redhat.com/security/cve/CVE-2026-33758
- https://bugzilla.redhat.com/show_bug.cgi?id=2452294
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33758.json
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33758.json