CVE-2026-55775: OpenBao's System Backend allows Unauthorized Management of the containing Namespace

Vulnerability summary

CVE-2026-55775 is a low (CVSS 2.3) Improper Authorization vulnerability in openbao. EPSS estimates a 0.48% chance of exploitation in the next 30 days, higher than 40.7% of scored vulnerabilities.

Timeline

1. 15-09-2026
   PublishedVulnerability first disclosed.
2. 15-09-2026
   Last modifiedVulnerability information updated.

Description

OpenBao is an open source identity-based secrets management system. Prior to 2.5.5, OpenBao users granted capabilities on /sys/namespaces/root within a non-root namespace could exploit special handling of the literal root path in namespace canonicalization. The /sys/namespaces/* endpoint family can resolve its containing namespace through a path prefix or X-Vault-Namespace header. ACL checks occurred before root canonicalized to an empty path, causing /sys/namespaces/root to resolve to the system backend's containing namespace and allowing permitted lookups, deletion, locking, or custom metadata changes against that direct containing namespace. The root namespace and arbitrary unrelated namespaces are not affected, and available operations depend on the capabilities granted on the path and subpaths such as /api-lock. This issue is fixed in version 2.5.5.

• CWE-285Improper AuthorizationThe product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.