Linux Distros Unpatched Vulnerability : CVE-2026-18663

medium Nessus Plugin ID 334909

Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

- A flaw was found in 389-ds-base. The get_ldapmessage_controls_ext() function frees the parsed controls array on the Session Tracking critical-control rejection path without clearing the SLAPI_REQCONTROLS pblock slot. Operation teardown then frees the same pointer again, causing a double-free. An unauthenticated remote attacker can trigger this with a single BIND request carrying a critical Session Tracking control, resulting in heap corruption and potential denial of service. (CVE-2026-18663)

Note that Nessus relies on the presence of the package as reported by the vendor.

Solution

There is no known solution at this time.

See Also

https://access.redhat.com/security/cve/cve-2026-18663

https://security-tracker.debian.org/tracker/CVE-2026-18663

https://ubuntu.com/security/CVE-2026-18663

Plugin Details

Severity: Medium

ID: 334909

File Name: unpatched_CVE_2026_18663.nasl

Version: 1.3

Type: Local

Agent: unix

Family: Misc.

Published: 8/12/2026

Updated: 8/13/2026

Supported Sensors: Agentless Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.72

CVSS v2

Risk Factor: High

Base Score: 8.5

Temporal Score: 7.2

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:C/A:P

CVSS Score Source: CVE-2026-18663

CVSS v3

Risk Factor: Medium

Base Score: 5.9

Temporal Score: 5.4

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:U/RC:C

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:16.04:-:lts, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, cpe:/o:canonical:ubuntu_linux:26.04:-:lts, cpe:/o:debian:debian_linux:11.0, cpe:/o:debian:debian_linux:12.0, cpe:/o:debian:debian_linux:13.0, cpe:/o:redhat:enterprise_linux:10, p-cpe:/a:canonical:ubuntu_linux:389-ds-base, p-cpe:/a:debian:debian_linux:389-ds-base, p-cpe:/a:redhat:enterprise_linux:389-ds-base-bdb, p-cpe:/a:redhat:enterprise_linux:389-ds-base-devel, p-cpe:/a:redhat:enterprise_linux:389-ds-base-libs, p-cpe:/a:redhat:enterprise_linux:389-ds-base-snmp, p-cpe:/a:redhat:enterprise_linux:389-ds-base, p-cpe:/a:redhat:enterprise_linux:python3-lib389

Required KB Items: Host/cpu, Host/local_checks_enabled, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 8/12/2026

Reference Information

CVE: CVE-2026-18663