Red Hat Directory Server/Enterprise Linux 389 Directory Server read_schema_dse heap-based overflow

Summaryinfo

A vulnerability was found in Red Hat Directory Server and Enterprise Linux. It has been rated as critical. This impacts the function read_schema_dse of the component 389 Directory Server. The manipulation leads to heap-based overflow. This vulnerability is documented as CVE-2026-11884. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Red Hat Directory Server and Enterprise Linux (version unknown). This issue affects the function read_schema_dse of the component 389 Directory Server. The manipulation with an unknown input leads to a heap-based overflow vulnerability. Using CWE to declare the problem leads to CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). Impacted is confidentiality, integrity, and availability. The summary by CVE is:

A heap buffer overflow flaw was found in 389 Directory Server. When serializing objectclass definitions, the oc_superior (SUP) field length is omitted from buffer size calculations in read_schema_dse() and schema_oc_to_string(), but the field is still written via strcat(). An attacker with Directory Manager privileges, or a compromised replication supplier, can trigger a server crash by creating objectclasses with long SUP values. This is an incomplete fix variant of CVE-2025-14905.

The advisory is shared at access.redhat.com. The identification of this vulnerability is CVE-2026-11884 since 06/10/2026. The exploitation is known to be easy. The attack may be initiated remotely. The exploitation needs additional levels of successful authentication. Technical details are known, but no exploit is available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 06/11/2026).

The vulnerability scanner Nessus provides a plugin with the ID 320432 (Linux Distros Unpatched Vulnerability : CVE-2026-11884), which helps to determine the existence of the flaw in a target environment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at Tenable (320432). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• Directory Service Software

Vendor

• Red Hat

Name

• Directory Server
• Enterprise Linux

License

• open-source

Website

• Vendor: https://www.redhat.com/

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Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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