Vulnerability · Published Sep 15, 2026 · Assigned by GitHub_M

CVE-2026-53658Fabric CA: LDAP Injection via Unescaped Username in GetUser Filter

Medium 6.3

In plain English

A medium-severity security flaw in fabric-ca from hyperledger. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 39% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)6.3Medium
Exploit odds (30 days)0.4%top 60.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Gogithub.com/hyperledger/fabric-ca1.5.21GHSA-xghw-p77p-3r7x
Gogithub.com/hyperledger/fabric-ca1.5.21GO-2026-6234

Affected products (as reported)

VendorProductVersions
hyperledger fabric-ca < 1.5.21

Weakness: CWE-90 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

References