Cross-namespace token disruption via unchecked accessor namespace
Published Apr 21, 2026 · Updated Apr 21, 2026
Improper token assignment in OpenBao before 2.5.3 allows remote authenticated users to renew or revoke tokens across namespaces. Token-store accessor paths perform renewal, revocation, or lookup without verifying that the request namespace matches the accessor's namespace. Exploitation requires a privileged administrator in one tenant and a leaked accessor from another, enabling token disruption without disclosure of the token value.
Summary
What happened
Improper token assignment in OpenBao before 2.5.3 allows remote authenticated users to renew or revoke tokens across namespaces. Token-store accessor paths perform renewal, revocation, or lookup without verifying that the request namespace matches the accessor's namespace. Exploitation requires a privileged administrator in one tenant and a leaked accessor from another, enabling token disruption without disclosure of the token value.
The record
- CVE
- CVE-2026-40264
- Published
- Apr 21, 2026
- Updated
- Apr 21, 2026
- Vendor
- OpenBao
- Product
- OpenBao
- Classifications
- CWE-1259, T1531
- Attack vector
- network
- Privileges
- admin
Timeline
How it unfolded
- Apr 21, 2026CVE publishedPublication date reported by the CVE source.
- Apr 21, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 2.5.3
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo