CVE-2026-33758
CVE-2026-33758 is a Improper Input Validation vulnerability in github.com/openbao/openbao. O3 Security confirms whether CVE-2026-33758 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
OpenBao has Reflected XSS in its OIDC authentication error message
Blast Radius
github.com/openbao/openbaoReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/openbao/openbao | all versions | 0.0.0-20260325133417-6e2b2dd84f0e |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/openbao/openbao. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/openbao/openbao to 0.0.0-20260325133417-6e2b2dd84f0e or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33758 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-33758 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-33758. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-33758 in your dependencies?
O3 detects CVE-2026-33758 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.