CVE-2026-76560 Red Hat CVE debrief

Who should care

Defenders responsible for 389 Directory Server instances, especially those exposed to untrusted LDAP clients, should assess their exposure and prioritize patching and configuration reviews.

Why it matters

This CVE allows unauthenticated clients to bypass access controls in 389 Directory Server, potentially leading to unauthorized directory modifications. Defenders should prioritize patching and reviewing access control configurations.

• Potential unauthorized directory modifications
• Bypass of intended access controls
• Increased risk of data tampering or unauthorized changes

Technical summary

The SELFDN ACI bind-rule evaluator in 389 Directory Server incorrectly matches an anonymous LDAP client's empty bind DN against an empty stored attribute value. This allows an unauthenticated client to perform operations restricted to a specific authenticated user, potentially leading to unauthorized directory modifications or data tampering. The vulnerability can be mitigated by verifying and patching affected systems, reviewing access control configurations, and monitoring LDAP client activity for potential abuse.

Defensive priority

Defenders should prioritize verifying and patching 389 Directory Server instances, especially those exposed to untrusted LDAP clients.

Recommended defensive actions

• Verify and apply patches for 389 Directory Server
• Review and update access control configurations for SELFDN ACI
• Monitor LDAP client activity for potential abuse
• Perform a thorough review of directory server configurations to ensure SELFDN ACI is properly implemented
• Conduct vulnerability scanning to identify potentially exposed systems
• Implement compensating controls for exposed systems while remediation is scheduled and verified
• Track exceptions and retest remediated assets

Evidence notes

The CVE record and NVD entry provide details on the flaw, but additional information on affected versions and remediation steps is limited. Further verification is needed to determine the full scope of affected systems and to confirm the efficacy of proposed mitigations. Defenders should verify patch application and review SELFDN ACI configurations for potential vulnerabilities.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.