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Linux Distros Unpatched Vulnerability : CVE-2026-121953

critical Nessus Plugin ID 376213

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.

 - FreeRDP before 3.32.2 has a use-after-free in the client's rdpgfx dynamic virtual channel: a duplicate- name channel with a new ChannelId overwrites the listener's single callback slot, which rdpgfx_on_close frees without clearing. A malicious RDP server can open and close such a channel, then send a PDU on the original channel to crash the client or potentially execute code. (CVE-2026-121953)

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-2026-121953

https://ubuntu.com/security/CVE-2026-121953

Plugin Details

Severity: Critical

ID: 376213

File Name: unpatched_CVE_2026_121953.nasl

Version: 1.2

Type: Local

Agent: unix

Family: Misc.

Published: 11/5/2026

Updated: 11/5/2026

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: Medium

Score: 4.9

Percentile: 58.51

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 9.3

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

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

CVSS Score Source: CVE-2026-121953

CVSS v4

Risk Factor: Critical

Base Score: 9.3

Threat Score: 8.9

Threat Vector: CVSS:4.0/E:P

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

CVSS Score Source: CVE-2026-121953

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:16.04:-:lts, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, cpe:/o:debian:debian_linux:12.0, cpe:/o:debian:debian_linux:13.0, p-cpe:/a:canonical:ubuntu_linux:freerdp, p-cpe:/a:debian:debian_linux:freerdp2, p-cpe:/a:debian:debian_linux:freerdp3

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: 11/4/2026

Reference Information

CVE: CVE-2026-121953