CVE-2026-53658

Fabric CA is a Certificate Authority for Hyperledger Fabric. Prior to 1.5.21, when fabric-ca is configured with an LDAP backend, Client.GetUser in lib/server/ldap/client.go inserts the username from HTTP Basic authentication into the LDAP uid search UserFilter without escaping LDAP metacharacters. An unauthenticated attacker with network access to the CA enrollment endpoint can alter the LDAP search before password validation and potentially steer authentication attempts toward a victim account. Deployments that do not use an LDAP backend are unaffected. This issue is fixed in version 1.5.21.

  • Published Sep 15, 2026
  • CVSS 6.3 medium
  • 0.4% chance of exploitation in the next 30 days (EPSS)
  • A fix is available

Affected software

CVE-2026-53658 at the National Vulnerability Database