CentOS Linux 7 [TuxCare] Security Update: tigervnc / tigervnc-icons / tigervnc-license / tigervnc-server / etc Multiple Vulnerabilities (CENTOS7:CLSA-2026:1779798274)

critical Nessus Plugin ID 359757

Synopsis

The CentOS Linux host is missing one or more security updates.

Description

The CentOS Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the TuxCare CENTOS7:CLSA-2026:1779798274 advisory.

- A use-after-free flaw was found in X.Org and Xwayland. The root cursor is referenced in the X server as a global variable. If a client frees the root cursor, the internal reference points to freed memory and causes a use-after-free. (CVE-2025-26594)

- A buffer overflow flaw was found in X.Org and Xwayland. The code in XkbVModMaskText() allocates a fixed- sized buffer on the stack and copies the names of the virtual modifiers to that buffer. The code fails to check the bounds of the buffer and would copy the data regardless of the size. (CVE-2025-26595)

- A heap overflow flaw was found in X.Org and Xwayland. The computation of the length in XkbSizeKeySyms() differs from what is written in XkbWriteKeySyms(), which may lead to a heap-based buffer overflow.
(CVE-2025-26596)

- A buffer overflow flaw was found in X.Org and Xwayland. If XkbChangeTypesOfKey() is called with a 0 group, it will resize the key symbols table to 0 but leave the key actions unchanged. If the same function is later called with a non-zero value of groups, this will cause a buffer overflow because the key actions are of the wrong size. (CVE-2025-26597)

- An out-of-bounds write flaw was found in X.Org and Xwayland. The function GetBarrierDevice() searches for the pointer device based on its device ID and returns the matching value, or supposedly NULL, if no match was found. However, the code will return the last element of the list if no matching device ID is found, which can lead to out-of-bounds memory access. (CVE-2025-26598)

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

Solution

Update the affected packages based on the guidance in TuxCare advisory CENTOS7:CLSA-2026:1779798274.

Plugin Details

Severity: Critical

ID: 359757

File Name: tuxcare_centos_7_CLSA-2026-1779798274.nasl

Version: 1.1

Type: Local

Agent: unix

Family: CentOS Local Security Checks

Published: 10/1/2026

Updated: 10/1/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.6

Percentile: 98.4

Vendor

Vendor Severity: Critical

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

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

CVSS Score Source: CVE-2026-34352

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

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:U/RL:O/RC:C

Vulnerability Information

Required KB Items: Host/local_checks_enabled, Host/CentOS/release, Host/CentOS/rpm-list, Host/OS/extended-third-party

Exploit Ease: No known exploits are available

Patch Publication Date: 5/26/2026

Vulnerability Publication Date: 2/18/2025

Reference Information

CVE: CVE-2025-26594, CVE-2025-26595, CVE-2025-26596, CVE-2025-26597, CVE-2025-26598, CVE-2025-26599, CVE-2025-26600, CVE-2025-26601, CVE-2025-49176, CVE-2025-49179, CVE-2025-49180, CVE-2025-62229, CVE-2025-62230, CVE-2025-62231, CVE-2026-34000, CVE-2026-34352

CLSA: 2026:1779798274

Detections

Analytics