Vulnerability details
CVE-2026-33758
openbao openbao
OpenBao has Reflected XSS in its OIDC authentication error message
CVSS 4.0
9.4Critical
Official description
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 scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 9.4Critical | 4.0 | CVEProject cvelistV5 (CNA) (GitHub_M) | 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 |
| 9.6Critical | 3.1 | CVEProject cvelistV5 (CNA) (redhat-SADP) | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| openbao | openbao | < 2.5.2 | CVEProject cvelistV5 (CNA) |
References and advisories
7- https://github.com/openbao/openbao/security/advisories/GHSA-cpj3-3r2f-xj59 x_refsource_CONFIRM
- https://github.com/openbao/openbao/pull/2709 x_refsource_MISC
- https://github.com/openbao/openbao/commit/6e2b2dd84f0e47cebc90d6e79609dd5274732662 x_refsource_MISC
- https://github.com/openbao/openbao/releases/tag/v2.5.2 x_refsource_MISC
- https://access.redhat.com/security/cve/CVE-2026-33758 vdb-entryx_refsource_REDHAT
- https://bugzilla.redhat.com/show_bug.cgi?id=2452294 issue-trackingx_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33758.json x_sadp-csaf-vex
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Details
- Published
- 2026-03-27
- Last updated
- 2026-07-15
- State
- Published
- Assigner (CNA)
- GitHub_M
Exploit prediction (EPSS)
0.29%
Probability of exploitation in 30 days
22.5%
Percentile (among all CVEs)
SSVC assessment (CISA)
- Automatable
- No
- Exploitation
- None
- Technical impact
- Total
Weaknesses (CWE)
- CWE-20Improper Input Validation
- CWE-116Improper Encoding or Escaping of Output
- CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')