CVE-2026-11793: redhat 389_directory_server Stack-based Buffer Overflow

Vulnerability summary

CVE-2026-11793 is a medium (CVSS 4.9) Stack-based Buffer Overflow vulnerability in redhat 389_directory_server. EPSS estimates a 0.28% chance of exploitation in the next 30 days, higher than 19.4% of scored vulnerabilities.

Timeline

1. 09-06-2026
   PublishedVulnerability first disclosed.
2. 07-08-2026
   Last modifiedVulnerability information updated.

Description

A stack buffer overflow flaw was found in 389 Directory Server. The checkPrefix() function in pw.c copies an attacker-controlled algorithm ID into a 256-byte stack buffer without bounds checking when parsing reversible-encrypted attribute values. An attacker with Directory Manager privileges can crash the LDAP server by storing a crafted credential with an oversized algorithm ID. FORTIFY_SOURCE mitigates this to denial of service only.

• CWE-121Stack-based Buffer OverflowA stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).