Critical 9.4Published Mar 27, 2026

CVE-2026-33758OpenBao has Reflected XSS in its OIDC authentication error message

Updated under an hour ago (Oct 26, 2026, 1:00 PM ET)

Does this affect you?

It affects openbao and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

Do this next

Start free and add your stack

Free account, 1 product

Every CVE for openbao

Exploited in the last 30 days

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: 9.4 CRITICAL (v4.0, CNA)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
Weakness (CWE): CWE-20, CWE-79, CWE-116
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Modified
Record last updated: Jul 14, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

openbao openbao openbao:openbao (from the name)	before 2.5.2	CNA record
Red Hat Cryostat 4 redhat:cryostat	4	CISA ADP
openbao openbao openbao:openbao	before 2.5.2	NVD

References

References

https://github.com/openbao/openbao/security/advisories/GHSA-cpj3-3r2f-xj59	x-refsource-confirm, vendor-advisory
https://github.com/openbao/openbao/pull/2709	x-refsource-misc, issue-tracking, patch
https://github.com/openbao/openbao/commit/6e2b2dd84f0e47cebc90d6e79609dd5274732662	x-refsource-misc, patch
https://github.com/openbao/openbao/releases/tag/v2.5.2	x-refsource-misc, product, release-notes
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

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.