CVE-2026-40264: Github.com/openbao/openbao OpenBao's Token Store Allows Cross-Namespace Vulnerability
LOWCVE-2026-40264 is a LOW openbao's token store allows cross-namespace vulnerability (CWE-1259: Improper Restriction of Security Token Assignment) affecting Github.com/openbao/openbao libraries in the Go ecosystem. The issue involves openbao's token store allows cross-namespace renewal, revocation. Remediation is available by upgrading affected packages to version 0.0.0-20260420162526-f58111d2ca54.
CVE-2026-40264 at a Glance
How to Fix CVE-2026-40264
To remediate this vulnerability, upgrade all affected Github.com/openbao/openbao dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade github.com/openbao/openbao to 0.0.0-20260420162526-f58111d2ca54Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for github.com/openbao/openbaoHow to Check if You Are Affected
To determine whether your application is affected by CVE-2026-40264, inspect your project dependencies for Github.com/openbao/openbao:
inspect dependencies for github.com/openbao/openbaoAnalyze the terminal output to locate any version of Github.com/openbao/openbao in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.0.0-20260420162526-f58111d2ca54), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-1259: Improper Restriction of Security Token Assignment, where the system-on-a-chip (soc) implements a security token mechanism to differentiate what actions are allowed or disallowed when a transaction originates from an entity. however, the security tokens are improperly protected. In Github.com/openbao/openbao, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-40264 Affected Github.com/openbao/openbao Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
github.com/openbao/openbao
|
Go |
< 0.0.0-20260420162526-f58111d2ca54
|
0.0.0-20260420162526-f58111d2ca54
|
References
Frequently Asked Questions
What is CVE-2026-40264?
Which Github.com/openbao/openbao versions are affected?
What version fixes CVE-2026-40264?
Is github.com/openbao/openbao affected?
What CWE is associated with CVE-2026-40264?
How can I check Go dependencies for CVE-2026-40264?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-p49j-v9wc-wg57",
"modified" : "2026-04-21T18:27:42Z",
"published" : "2026-04-21T18:27:42Z",
"aliases" : [ "CVE-2026-40264" ],
"summary" : "OpenBao's Token Store Allows Cross-Namespace Renewal, Revocation",
"details" : "### Impact\n\nOpenBao's namespaces provide multi-tenant separation. A tenant who leaks token accessors can have their token revoked or renewed by a privileged administrator in another tenant.\n\n### Patches\n\nThis was addressed in v2.5.3.",
"severity" : [ {
"type" : "CVSS_V4",
"score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/openbao/openbao"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "0.0.0-20260420162526-f58111d2ca54"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/openbao/openbao/security/advisories/GHSA-p49j-v9wc-wg57"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-40264"
}, {
"type" : "WEB",
"url" : "https://github.com/openbao/openbao/pull/2934"
}, {
"type" : "WEB",
"url" : "https://github.com/openbao/openbao/commit/059cc5950303688335d5c8ab9af8e453795d693a"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/openbao/openbao"
}, {
"type" : "WEB",
"url" : "https://github.com/openbao/openbao/releases/tag/v2.5.3"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-1259" ],
"severity" : "LOW",
"github_reviewed" : true,
"github_reviewed_at" : "2026-04-21T18:27:42Z",
"nvd_published_at" : "2026-04-21T01:16:06Z"
}
}