CVE-2026-33758
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.29%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 4.0
- 9.4 CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.29% probability · 21th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-20, CWE-79, CWE-116
- Affected
- openbao/openbao
- Source
- security-advisories@github.com
References
- https://github.com/openbao/openbao/commit/6e2b2dd84f0e47cebc90d6e79609dd5274732662Patch
- https://github.com/openbao/openbao/pull/2709Issue Tracking, Patch
- https://github.com/openbao/openbao/releases/tag/v2.5.2Product, Release Notes
- https://github.com/openbao/openbao/security/advisories/GHSA-cpj3-3r2f-xj59Vendor Advisory
- https://access.redhat.com/security/cve/CVE-2026-33758
- https://bugzilla.redhat.com/show_bug.cgi?id=2452294
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33758.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.