CVE-2026-55774: OpenBao: Cross-namespace lease revocation/renewal via canonical sys/leases/{revoke,renew} — incomplete fix of CVE-2026-45808

Vulnerability summary

CVE-2026-55774 is a low (CVSS 2.1) Incorrect Authorization vulnerability in openbao. EPSS estimates a 0.56% chance of exploitation in the next 30 days, higher than 45.9% 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, an OpenBao user with access to sys/leases/revoke/:lease_id in one namespace could revoke a lease in another namespace when the foreign lease_id was known, bypassing namespace ACL isolation. The affected lease lookup routing in vault/expiration.go allowed FetchLeaseInfo and loadEntry to resolve cached or stored lease data outside the request namespace, allowing a tenant that intentionally disclosed a lease identifier to have the lease and its underlying credential revoked by another tenant. This issue is fixed in version 2.5.5.

• CWE-863Incorrect AuthorizationThe product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.