CVE-2026-90979 Apache Software Foundation CVE debrief

Who should care

Defenders responsible for LDAP-based authentication and role management systems should assess exposure and prioritize patching or mitigation. This includes administrators of systems using GSSAPILdapLoginModule or LDAPBackingEngine directly, as well as security teams managing LDAP filter templates and login activities.

Why it matters

CVE-2026-90979 is a vulnerability in LDAPCache and LDAPBackingEngine that allows for LDAP search filter injection, potentially leading to over-granting of roles or incorrect login resolution. Defenders should prioritize verifying and patching affected systems, especially those using GSSAPILdapLoginModule or LDAPBackingEngine directly. Evidence is limited, and further verification is required to determine affected versions and exploitation.

• Potential for unauthorized role escalation through LDAP search filter manipulation.
• Possible incorrect login resolution due to filter structure alteration.
• Need for verification of affected versions and systems using GSSAPILdapLoginModule or LDAPBackingEngine directly.
• Priority for updating LDAP filter templates and monitoring login activities.

Technical summary

LDAPCache and LDAPBackingEngine build LDAP search filters by textually substituting placeholders with user input. Before the fix, only double backslash escaping was applied, which does not escape RFC 4515 required characters (*, (, ), and NUL). This allows a crafted username to alter the filter structure, potentially widening search results and over-granting roles. The issue affects systems using GSSAPILdapLoginModule or LDAPBackingEngine directly, and defenders should prioritize verifying and patching affected systems.

Defensive priority

Defenders should prioritize verifying and patching affected systems, especially those using GSSAPILdapLoginModule or LDAPBackingEngine directly.

Recommended defensive actions

• Verify and apply patches for affected systems, especially those using GSSAPILdapLoginModule or LDAPBackingEngine directly.
• Review and update LDAP filter templates to ensure proper escaping of special characters.
• Monitor login and role lookup activities for potential anomalies.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The CVE record and vendor information indicate a potential vulnerability in LDAP search filter handling. Details on affected versions and exploitation are limited, but defenders should verify and patch affected systems, especially those using GSSAPILdapLoginModule or LDAPBackingEngine directly. Evidence is limited, and further verification is required to determine affected versions and exploitation.

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.