Linux Distros Unpatched Vulnerability : CVE-2026-50736

critical Nessus Plugin ID 330654

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.

- The pglogical queue mechanism, used to convey out-of-band commands such as replicated DDL from a publisher to a subscriber, executes message payloads on the subscriber at the privilege level of the apply worker, which is equivalent to a PostgreSQL superuser in default installations. A party acting as the publisher can send crafted queue messages that cause arbitrary SQL to be executed on the subscriber as superuser, escalating from a role permitted to use pglogical to full superuser and breaking the isolation between tenants in shared deployments. To exploit the issue an attacker must be able to direct a subscription at an endpoint they control. In default installations this requires privileges normally reserved for a superuser, so the issue is most relevant to managed deployments where the ability to create subscriptions has been delegated to non-superuser roles. (CVE-2026-50736)

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://security-tracker.debian.org/tracker/CVE-2026-50736

https://ubuntu.com/security/CVE-2026-50736

Plugin Details

Severity: Critical

ID: 330654

File Name: unpatched_CVE_2026_50736.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Misc.

Published: 7/29/2026

Updated: 7/29/2026

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.15

CVSS v2

Risk Factor: High

Base Score: 8

Temporal Score: 6.8

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

CVSS Score Source: CVE-2026-50736

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 8.1

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

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

CVSS v4

Risk Factor: Critical

Base Score: 9

Threat Score: 6.1

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

Vulnerability Information

CPE: 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:debian:debian_linux:14.0, p-cpe:/a:canonical:ubuntu_linux:pglogical, p-cpe:/a:debian:debian_linux:pglogical

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: 7/28/2026

Reference Information

CVE: CVE-2026-50736