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OpenAdvisories
High RLSA-2026:98538 8 CVEs

Important: tigervnc security update

Published Nov 13, 2026 · Updated Nov 13, 2026

Ecosystem: Rocky Linux

Summary

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 input_constrain_cursor() (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.

Fixed packages 39

ReleasePackageFixed in
Rocky Linux · 9 tigervnc 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-debuginfo 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-debuginfo 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-debuginfo 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-debuginfo 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-debugsource 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-debugsource 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-debugsource 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-debugsource 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-icons 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-license 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-selinux 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server-debuginfo 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server-debuginfo 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server-debuginfo 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server-debuginfo 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server-minimal 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server-minimal 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server-minimal 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server-minimal 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server-minimal-debuginfo 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server-minimal-debuginfo 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server-minimal-debuginfo 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server-minimal-debuginfo 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server-module 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server-module 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server-module 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server-module 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server-module-debuginfo 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server-module-debuginfo 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server-module-debuginfo 0:1.16.2-4.el9_9.1
Rocky Linux · 9 tigervnc-server-module-debuginfo 0:1.16.2-4.el9_9.1

Vulnerabilities 8

  • High 8.5
    CVE-2026-93517

    X.Org Server GLX RenderLarge Heap Buffer Overflow

    A heap buffer overflow in handling GLX RenderLarge request where dataBytes exceeds cmdlen in X.org X server before 21.1.25 and XWayland before 24.1.14 that could be be triggered by an authenticated X client could cause crashes or code execution in X server co…

    X.Org x.orgg xwayland xorg-x11-server Debian Ubuntu Azure Linux Alpine
  • High 7.8
    CVE-2026-88812

    X.Org Server XKB SetGeometry TextDoodad Double Free

    A double free in XKB SetGeometryin X.Org X Server before 21.1.25 and X Wayland before 24.1.14 could be used by attached clients to cause a crash or potentially code in the x server context.

    X.Org xwayland xorg-x11-server xorg-server Debian Ubuntu Azure Linux Alpine
  • High 7.8
    CVE-2026-93518

    X.Org Server XKB ResizeKeyType Numeric Truncation

    An integer truncation issue in XkbResizeKeyType() that could lead to a heap buffer overflow by authenticated X clients in X.org X server before 21.1.25 and XWayland before 24.1.14 could be exploited for crashes or potential code execution in the X server.

    X.Org xwayland xorg-x11-server xorg-server Debian Ubuntu Azure Linux Alpine
  • High 7.8
    CVE-2026-93519

    X.Org Server XFixes Pointer Barrier Event List Buffer Overflow

    A buffer overflow when handling pointer barriers in the XFIXES extension in X.Org X server before 21.1.25 and XWayland before 24.1.14 could be used by authenticated X clients to crash or potentially execute code in X server context.

    X.Org x.orgg xorg-x11-server xwayland Debian Ubuntu Azure Linux Alpine
  • High 7.8
    CVE-2026-93520

    X.Org Server XKB ChangeKeycodeRange Heap Out-of-Bounds Write

    A heap buffer overflow caused by mismatching size calculations between XkbAllocNames and ChangeKeycodeRange in X.org X server before 2.1.25 and XWayland before 24.1.14 could be used by authenticated X clients to crash or potentially execute code in X server c…

    X.Org xwayland xorg-x11-server xorg-server Debian Ubuntu Azure Linux Alpine
  • High 7.8
    CVE-2026-93521

    X.Org Server RandR ChangeProviderProperty Heap Buffer Overflow

    A buffer overflow in RandR ChangeProviderProperty requests in X.Org X Server before 2.1.25 and XWayland before 24.4.14 could be used by authenticated X clients to crash or execute code within the X server context.

    X.Org xwayland xorg-x11-server xorg-server Debian Ubuntu Azure Linux Alpine
  • High 7.8
    CVE-2026-93523

    X.Org Server XInput2 PassiveUngrabDevice Out-of-Bounds Write

    A heap buffer overflow caused by a XIPassiveUngrabDevice request with an out-of-range modifier value in X.Org X Server before 21.1.15 and XWayland before 24.1.14 could be used by authenticated X clients to crash or potentially execute code in X server context.

    X.Org xwayland xorg-x11-server xorg-server Debian Ubuntu Azure Linux Alpine
  • Medium 5.5
    CVE-2026-93516

    .Org Server XInput Passive Grab Use-After-Free

    A use-after-free caused by lack of lifecycle management when adding / removing XInput master devices in X.org X Server before 21.1.25 and XWayland before 24.1.14 could be used by authenticated X Clients to crash the X server or potentially execute code in X s…

    X.Org xwayland xorg-x11-server xorg-server Debian Ubuntu Azure Linux Alpine

References

  • report
    https://bugzilla.redhat.com/show_bug.cgi?id=2545161
  • report
    https://bugzilla.redhat.com/show_bug.cgi?id=2545164
  • report
    https://bugzilla.redhat.com/show_bug.cgi?id=2545174
  • report
    https://bugzilla.redhat.com/show_bug.cgi?id=2545177
  • report
    https://bugzilla.redhat.com/show_bug.cgi?id=2545246
  • report
    https://bugzilla.redhat.com/show_bug.cgi?id=2545860
  • report
    https://bugzilla.redhat.com/show_bug.cgi?id=2545887
  • report
    https://bugzilla.redhat.com/show_bug.cgi?id=2545908
  • advisory
    https://access.redhat.com/errata/RHSA-2026:98538