OpenBao LIST ACL bypass: a trailing-slash LIST request skips a more-specific deny rule (unported Vault v2.0.3 fix)

OpenBao is an open source identity-based secrets management system. Prior to 2.6.0, OpenBao's vault/policy/acl.go could evaluate a broader wildcard ACL grant before more-specific trailing-wildcard ACL paths with capabilities = ["deny"] for a LIST operation. When a parent path permitted LIST and a child path was denied, the trailing-slash lookup could therefore allow listing the denied path. Other operation types are outside the repository advisory's affected scope. This issue is fixed in version 2.6.0.