Status: UPDATED
| Advisory ID: CVE-2026-18355
Key Details
| CVE | CVE-2026-18355 |
| CVSS Score / Version | 7.5 (High) / CVSS v3.1 |
| Updated | 2026-10-08 |
| CVSS Vector | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |
| CVSS Prose | attack vector is network; attack complexity is high; privileges required is low; user interaction is none; scope is unchanged; confidentiality impact is high; integrity impact is high; availability impact is high. |
| Affected products | see table below |
| Classified as | CWE-191 (Integer Underflow (Wrap or Wraparound)) |
Affected Products, Subsystems & Sectors
| Subsystems | OT Supporting Infrastructure |
| Sectors | Multiple |
What to Know
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. (NVD)
What to Do
Monitor Red Hat's web page for any future patch releases.
References