CVE-2026-55770: OpenBao: LDAPi ldaputil (wrong escape func)

Vulnerability summary

CVE-2026-55770 is a medium (CVSS 6.8) LDAP Injection vulnerability in openbao. EPSS estimates a 0.53% chance of exploitation in the next 30 days, higher than 43.6% of scored vulnerabilities.

Timeline

1. 15-09-2026
   PublishedVulnerability first disclosed.
2. 17-09-2026
   Last modifiedVulnerability information updated.

Description

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.

• CWE-90Improper Neutralization of Special Elements used in an LDAP Query ('LDAP Injection')The product constructs all or part of an LDAP query using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended LDAP query when it is sent to a downstream component.