ALSA-2026:99623: Important: tigervnc security update
Virtual Network Computing (VNC) is a remote display system which allows users to view a computing desktop environment not only on the machine where it is running, but from anywhere on the Internet and from a wide variety of machine architectures. TigerVNC is a suite of VNC servers and clients.
Security Fix(es):
xorg-x11-server: xorg-x11-server: Arbitrary code execution via use-after-free in passive grab handling (CVE-2026-93516) xorg-x11-server: xorg-x11-server: Privilege escalation via crafted RandR provider property requests (CVE-2026-93521) xorg-x11-server: xwayland: xorg-x11-server: Arbitrary code execution via double-free in XKB geometry handling (CVE-2026-88812) xorg-x11-server: xorg-x11-server: Out-of-bounds write via unvalidated modifier in ProcXIPassiveUngrabDevice (CVE-2026-93523) xorg-x11-server: xorg-x11-server: arbitrary code execution via GLX RenderLarge heap-based buffer overflow (CVE-2026-93517) xorg-x11-server: xorg-x11-server: arbitrary code execution via integer truncation during keyboard mapping resize (CVE-2026-93518) xorg-x11-server: xorg-x11-server: Arbitrary code execution via buffer overflow in inputconstraincursor() (CVE-2026-93519) xorg-x11-server: xorg-x11-server: arbitrary code execution via out-of-bounds write in XKB keycode handling (CVE-2026-93520)
For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
almalinux/tigervncto a version that resolves this vulnerability.Fixed in 1.15.0-11.el8_10 - Upgrade
Upgrade
almalinux/tigervnc-iconsto a version that resolves this vulnerability.Fixed in 1.15.0-11.el8_10 - Upgrade
Upgrade
almalinux/tigervnc-licenseto a version that resolves this vulnerability.Fixed in 1.15.0-11.el8_10 - Upgrade
Upgrade
almalinux/tigervnc-selinuxto a version that resolves this vulnerability.Fixed in 1.15.0-11.el8_10 - Upgrade
Upgrade
almalinux/tigervnc-serverto a version that resolves this vulnerability.Fixed in 1.15.0-11.el8_10 - Upgrade
Upgrade
almalinux/tigervnc-server-minimalto a version that resolves this vulnerability.Fixed in 1.15.0-11.el8_10 - Upgrade
Upgrade
almalinux/tigervnc-server-moduleto a version that resolves this vulnerability.Fixed in 1.15.0-11.el8_10
Event History
Child vulnerabilities
Contains the following vulnerabilities.
Frequently Asked Questions
Which components are implicated by the listed security fixes?
The listed fixes affect xorg-x11-server, including xwayland for CVE-2026-88812. The advisory applies to the listed AlmaLinux TigerVNC packages, including tigervnc-server, tigervnc-server-minimal, tigervnc-server-module, tigervnc-selinux, tigervnc-icons, and tigervnc-license.
What kinds of impact are addressed by this update?
The advisory lists arbitrary code execution, privilege escalation, and an out-of-bounds write. The underlying flaw types include use-after-free, double-free, buffer overflow, heap-based buffer overflow, integer truncation, and unvalidated input handling.