CVE-2026-55770

OpenBao is an open source identity-based secrets management system. Prior to 2.5.5, OpenBao used EscapeLDAPValue, an RFC 4514 distinguished-name escaping function, where RFC 4515 LDAP search-filter escaping was required in sdk/helper/ldaputil/client.go GetUserDN. With the LDAP authentication backend configured for an Active Directory UPNDomain path or UserDN and UserAttr binding, an attacker-controlled username containing filter metacharacters could alter the search predicate and select a different directory entry because EscapeLDAPValue does not neutralize the characters handled by ldap.EscapeFilter. A resulting token could be associated with another LDAP identity and gain access to secrets, policies, or modification capabilities assigned to that identity. This issue is fixed in version 2.5.5.

• https://github.com/openbao/openbao/commit/10b7825c714c1ef25b6c3c1c2cd6ecd8747c0659
• https://github.com/openbao/openbao/commit/8077f96bdc02137b0a072146b6f9ca11c96c549c
• https://github.com/openbao/openbao/pull/3306
• https://github.com/openbao/openbao/pull/3313
• https://github.com/openbao/openbao/releases/tag/v2.5.5
• https://github.com/openbao/openbao/releases/tag/v2.6.0
• https://github.com/openbao/openbao/security/advisories/GHSA-6mwx-4547-5vc9
• https://github.com/openbao/openbao/security/advisories/GHSA-6mwx-4547-5vc9