Debian dsa-6370 : xnest - security update

high Nessus Plugin ID 323053

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Synopsis

The remote Debian host is missing one or more security-related updates.

Description

The remote Debian 13 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-6370 advisory.

- ------------------------------------------------------------------------- Debian Security Advisory DSA-6370-1 [email protected] https://www.debian.org/security/ Salvatore Bonaccorso June 27, 2026 https://www.debian.org/security/faq
- -------------------------------------------------------------------------

Package : xorg-server CVE ID : CVE-2026-50256 CVE-2026-50257 CVE-2026-50258 CVE-2026-50259 CVE-2026-50260 CVE-2026-50261 CVE-2026-50262 CVE-2026-50263 CVE-2026-50264 Debian Bug : 1138680

Several vulnerabilities were discovered in the Xorg X server, which may result in privilege escalation if the X server is running privileged.

For the stable distribution (trixie), these problems have been fixed in version 2:21.1.16-1.3+deb13u3.

We recommend that you upgrade your xorg-server packages.

For the detailed security status of xorg-server please refer to its security tracker page at:
https://security-tracker.debian.org/tracker/xorg-server

Further information about Debian Security Advisories, how to apply these updates to your system and frequently asked questions can be found at: https://www.debian.org/security/

Mailing list: [email protected]

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Upgrade the xnest packages.

Plugin Details

Severity: High

ID: 323053

File Name: debian_DSA-6370.nasl

Version: 1.2

Type: Local

Agent: unix

Family: Debian Local Security Checks

Published: 6/26/2026

Updated: 6/27/2026

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

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 57.98

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

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

CVSS Score Source: CVE-2026-50264

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

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

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

Vulnerability Information

CPE: p-cpe:/a:debian:debian_linux:xnest, p-cpe:/a:debian:debian_linux:xserver-common, p-cpe:/a:debian:debian_linux:xserver-xephyr, p-cpe:/a:debian:debian_linux:xserver-xorg-core, p-cpe:/a:debian:debian_linux:xserver-xorg-core-udeb, p-cpe:/a:debian:debian_linux:xserver-xorg-dev, p-cpe:/a:debian:debian_linux:xvfb, p-cpe:/a:debian:debian_linux:xorg-server-source, p-cpe:/a:debian:debian_linux:xserver-xorg-legacy, cpe:/o:debian:debian_linux:13.0

Required KB Items: Host/local_checks_enabled, Host/Debian/release, Host/Debian/dpkg-l

Exploit Ease: No known exploits are available

Patch Publication Date: 6/26/2026

Vulnerability Publication Date: 6/26/2026

Reference Information

CVE: CVE-2026-50256, CVE-2026-50257, CVE-2026-50258, CVE-2026-50259, CVE-2026-50260, CVE-2026-50261, CVE-2026-50262, CVE-2026-50263, CVE-2026-50264

Detections

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