A heap buffer overflow vulnerability (CVE-2025-14905) was identified in the 389-ds-base server used by Red Hat Directory Server 11.5 E4S for RHEL 8. The vulnerability arises from improper calculation of buffer size in the schema_attr_enum_callback function within schema.c, where alias string lengths are summed without accounting for additional formatting characters. When processing many aliases, this can overflow the heap buffer, potentially enabling remote code execution or denial of service. Red Hat has released security updates for 389-ds-base packages on Red Hat Enterprise Linux 9 and 10, with patches available for multiple architectures. The vendor advisory classifies the impact as Moderate and provides detailed instructions for applying the fixes.

The vulnerability can lead to remote code execution or denial of service on affected Red Hat Directory Server installations. The CVSS score of 7.2 reflects high severity with network attack vector, low attack complexity, high confidentiality, integrity, and availability impacts. However, Red Hat rates the security impact as Moderate in their advisories. There are no known exploits in the wild at this time. The issue affects multiple Red Hat Enterprise Linux versions and architectures where 389-ds-base is deployed.

Red Hat has released official security updates for 389-ds-base packages on Red Hat Enterprise Linux 9 and 10 that address CVE-2025-14905. Users should apply these updates promptly following the instructions in the Red Hat advisories (RHSA-2026:3189 and RHSA-2026:3208) and the knowledge base article https://access.redhat.com/articles/11258. No additional mitigation steps are indicated or required beyond applying the vendor-provided patches.