CVE-2026-74241 in OpenShift Update Service
Summary
by MITRE • 08/15/2026
A flaw was found in Red Hat Quay's external Lightweight Directory Access Protocol (LDAP) authentication handling. When an LDAP referral is returned during authentication, the system does not properly escape the username input. This allows an attacker to inject LDAP filter metacharacters, enabling user-existence oracle attacks at the referral Directory Name (DN). This could also potentially influence which DN is used for password binding in multi-domain Active Directory environments.
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Analysis
by VulDB Data Team • 08/15/2026
This vulnerability exists within Red Hat Quay's authentication infrastructure where external Lightweight Directory Access Protocol integration fails to properly sanitize user inputs during LDAP referral processing. The flaw represents a classic input validation issue that enables attackers to manipulate LDAP filter syntax through carefully crafted username inputs. When the system encounters an LDAP referral response, it processes the username without adequate escaping mechanisms, creating opportunities for malicious input injection that can bypass normal authentication boundaries.
The technical exploitation occurs through LDAP filter metacharacters such as parentheses, asterisks, and other special characters that can alter the intended query behavior. This vulnerability specifically targets the Directory Name (DN) processing within referral responses, allowing attackers to determine whether specific user accounts exist within the directory service without proper authorization. The issue manifests as an oracle attack pattern where successful authentication attempts versus failed ones reveal information about account existence, creating a reconnaissance vector for further attacks.
From an operational impact perspective, this vulnerability undermines fundamental authentication security controls by enabling unauthorized discovery of valid user accounts and potentially exposing organizational directory structure information. In multi-domain Active Directory environments, the flaw could allow attackers to manipulate which directory entries are targeted during password binding operations, potentially enabling privilege escalation or cross-domain access attempts. The vulnerability affects the core authentication flow and can be exploited even when traditional access controls might otherwise prevent unauthorized access.
The security implications extend beyond simple account enumeration to potentially enable more sophisticated attacks such as password spraying or credential stuffing against discovered valid accounts. Organizations using Red Hat Quay with LDAP integration face increased risk of successful compromise attempts, particularly in environments where directory services are not properly segmented or monitored for unusual authentication patterns. This vulnerability aligns with CWE-77 and CWE-20 categories related to input validation and improper escaping of special characters in directory access protocols.
Mitigation strategies should focus on implementing proper input sanitization mechanisms that escape or filter LDAP metacharacters before processing user inputs during referral handling. Organizations should consider updating to patched versions of Red Hat Quay where the issue has been addressed through proper input validation controls. Network segmentation and monitoring of authentication patterns can help detect anomalous behavior indicative of exploitation attempts. Additionally, implementing rate limiting and account lockout mechanisms can reduce the effectiveness of automated enumeration attacks while maintaining operational security posture against this class of vulnerability.