SEPTEMBER 17, 2026
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Case File

CVE-2026-18355

HIGH · CVSS 7.5 EPSS 0.84% Public Exploit

Source: NVD + CISA KEV + EPSS · Published 2026-09-07 · Last synced 2026-09-17

CyberRota Analysis

AI-Generated

A heap buffer overflow vulnerability exists in the SASL I/O layer of the 389 Directory Server, where improper validation of packet lengths can lead to an attacker-controlled overflow. This flaw allows a remote authenticated attacker to potentially execute arbitrary code or cause a denial of service after a successful SASL bind with integrity protection. Organizations using 389 Directory Server should prioritize patching this vulnerability to mitigate the risk of exploitation.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Detected Signals
remote code execution code execution

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2026-18355
Severity
HIGH
CVSS
7.5
EPSS
0.84%

Original NVD Description

A heap buffer overflow flaw was found in the SASL I/O layer of 389 Directory Server (389-ds-base). In sasl_io_start_packet(), the wrapped-record length read from the wire is validated only against an upper bound. A small wire length (0, 1, or 2) produces an encrypted_buffer_count below the already-consumed encrypted_buffer_offset, causing an unsigned subtraction underflow in sasl_io_read_packet(). PR_Recv is then requested to read approximately 4 GiB into a 1024-byte heap buffer, resulting in a heap buffer overflow with attacker-controlled content. After a successful SASL bind with integrity protection (SSF > 0), a remote authenticated attacker can cause a denial of service or potentially achieve remote code execution. This flaw is distinct from CVE-2026-11774, whose fix only guards against upper-bound overflow.