How severe is CVE-2026-40264?

No CVSS score has been assigned to CVE-2026-40264 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-40264?

CVE-2026-40264 affects the following packages: github.com/openbao/openbao (Go). Ecosystems affected: Go.

How do I fix CVE-2026-40264?

Update github.com/openbao/openbao to 0.0.0-20260420162526-f58111d2ca54 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-40264 is resolved across your whole dependency graph.

How do I detect CVE-2026-40264 in my Go dependencies?

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.

How do I mitigate CVE-2026-40264 if there is no patch (or I can't update yet)?

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 does O3 Security protect against CVE-2026-40264?

O3 pinpoints whether CVE-2026-40264 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2026-40264 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-40264 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was CVE-2026-40264 published, and has it been updated?

CVE-2026-40264 was published on April 21, 2026 and was last updated on July 31, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

CVE-2026-40264

CVE-2026-40264 is a security vulnerability in github.com/openbao/openbao. O3 Security confirms whether CVE-2026-40264 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

OpenBao's Token Store Allows Cross-Namespace Renewal, Revocation

Also known asBIT-openbao-2026-40264GHSA-p49j-v9wc-wg57GO-2026-5526

Published

Apr 21, 2026

Updated

Jul 31, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Blast Radius

1 pkg affected

🐹github.com/openbao/openbao

Real-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. OpenBao's namespaces provide multi-tenant separation. Prior to version 2.5.3, a tenant who leaks token accessors can have their token revoked or renewed by a privileged administrator in another tenant. This is addressed in v2.5.3.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/openbao/openbao`	all versions	0.0.0-20260420162526-f58111d2ca54

Detection & mitigation playbook

Open-source dependency

Detect
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 0.0.0-20260420162526-f58111d2ca54 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-40264 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-2026-40264 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-2026-40264. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2026-40264 in your dependencies?

O3 detects CVE-2026-40264 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works