A flaw was found in OpenLDAP in versions before 2.4.56. This flaw allows an attacker who sends a malicious packet processed by OpenLDAP to force a failed assertion in csnNormalize23(). The highest threat from this vulnerability is to system availability.
An official patch is available. Apply the patch as soon as possible.
CVSS v4.0 Metrics
Exploitability
Attack VectorNetwork
ComplexityLow
RequirementsPresent
PrivilegesNone
User InteractionNone
Threat
Exploit MaturityUnreported
Vulnerable System
ConfidentialityNone
IntegrityNone
AvailabilityHigh
Subsequent System
ConfidentialityNone
IntegrityNone
AvailabilityNone
Supplemental
SafetyNegligible
AutomatableYes
RecoveryAutomatic
Value DensityConcentrated
UrgencyMedium
Patch StatusOfficial Patch
Change Log
| Date | Source | Changes | Score |
|---|
| 2026-07-21 | nvd | AV: P→N, AC: H→L, PR: H→N, UI: A→N, VA: N→H | 0.0 → 4.6 |
| 2026-07-21 | nvd | patch: Unavailable→Official Patch | 0.0 → 0.0 |
| 2026-07-21 | cve.org | initial, patch: Unavailable | 0.0 |
Affected Software
| Vendor | Product | Version |
|---|
| debian | debian_linux | 9.0 |
| fedoraproject | fedora | 33 |
| n/a | openldap | openldap 2.4.56 |
| openldap | openldap | < 2.4.56 |
| redhat | enterprise_linux | 5.0 |
| redhat | enterprise_linux | 6.0 |
| redhat | enterprise_linux | 7.0 |
| redhat | jboss_core_services | All versions |
| redhat | jboss_enterprise_application_platform | 5.0.0 |
| redhat | jboss_enterprise_web_server | 2.0.0 |
Published: 2021-05-28
