Astra Linux – Vulnerability in libx11, libxpm

A vulnerability was discovered in libX11 due to an infinite loop within the PutSubImage function. This flaw allows a local user to consume all available system resources and cause a denial of service condition...

Astra Linux – Vulnerability in Firefox and Thunderbird

When using X11, text selected by the page using the Selection API is erroneously copied into the primary selection, a temporary storage similar to the clipboard. This bug only affects Firefox on X11. Other systems are unaffected. This vulnerability affects Firefox versions earlier than 120, Firef...

xorg: xwayland: X.Org X server: Denial of Service via integer underflow in XKB compatibility map handling

A flaw was found in the X.Org X server. This integer underflow vulnerability, specifically in the XKB compatibility map handling, allows an attacker with local or remote X11 server access to trigger a buffer read overrun. This can lead to memory-safety violations and potentially a denial of servi...

xorg: xwayland: X.Org X server: Denial of Service via integer underflow in XKB compatibility map handling

A flaw was found in the X.Org X server. This integer underflow vulnerability, specifically in the XKB compatibility map handling, allows an attacker with local or remote X11 server access to trigger a buffer read overrun. This can lead to memory-safety violations and potentially a denial of servi...

JLSEC-2026-472

A vulnerability was found in libX11. The security flaw occurs because the functions in src/InitExt.c in libX11 do not check that the values provided for the Request, Event, or Error IDs are within the bounds of the arrays that those functions write to, using those IDs as array indexes. They trust...

JLSEC-2026-471

LookupCol.c in X.Org X through X11R7.7 and libX11 before 1.7.1 might allow remote attackers to execute arbitrary code. The libX11 XLookupColor request intended for server-side color lookup contains a flaw allowing a client to send color-name requests with a name longer than the maximum size allow...

[SECURITY] Fedora 42 Update: xorg-x11-server-Xwayland-24.1.11-1.fc42

Xwayland is an X server for running X clients under Wayland...

RockyLinux 8 : tigervnc (RLSA-2026:13414)

The remote RockyLinux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RLSA-2026:13414 advisory. xorg: xwayland: X.Org X server: Denial of Service via integer underflow in XKB compatibility map handling CVE-2026-33999 xorg: xwayland: X.Org X server:...

EUVD-2026-27343

A flaw was found in the X.Org X server. This vulnerability, an out-of-bounds read, affects the XKB X Keyboard Extension modifier map handling. An attacker with access to the X11 server can exploit this by sending a malformed request, which causes the server to read beyond its intended memory...

xorg: xwayland: X.Org X server: Use-after-free vulnerability leads to server crash and potential memory corruption

A flaw was found in the X.Org X server. This use-after-free vulnerability occurs in the XSYNC fence triggering logic, specifically within the miSyncTriggerFence function. An attacker with access to the X11 server can exploit this without user interaction, leading to a server crash and potentially...

OESA-2026-2143 xorg-x11-server-xwayland security update

Xwayland is an X server for running X clients under Wayland. %package devel Summary: Development package Requires: pkgconfig %description devel The development package provides the developmental files which are necessary for developing Wayland compositors using Xwayland. %prep %autosetup -n...

Important: xorg-x11-server

Issue Overview: XKB Integer Underflow in XkbSetCompatMap CVE-2026-33999 XKB Out-of-bounds Read in CheckSetGeom CVE-2026-34000 XSYNC Use-after-free in miSyncTriggerFence CVE-2026-34001 XKB Out-of-bounds read in CheckModifierMap CVE-2026-34002 XKB Buffer overflow in CheckKeyTypes CVE-2026-34003...

AlmaLinux 9 : tigervnc (ALSA-2026:10739)

The remote AlmaLinux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the ALSA-2026:10739 advisory. xorg: xwayland: X.Org X server: Denial of Service via integer underflow in XKB compatibility map handling CVE-2026-33999 xorg: xwayland: X.Org X server:...

xorg: xwayland: X.Org X server: Denial of Service via integer underflow in XKB compatibility map handling

A flaw was found in the X.Org X server. This integer underflow vulnerability, specifically in the XKB compatibility map handling, allows an attacker with local or remote X11 server access to trigger a buffer read overrun. This can lead to memory-safety violations and potentially a denial of servi...

xorg: xwayland: X.Org X server: Use-after-free vulnerability leads to server crash and potential memory corruption

A flaw was found in the X.Org X server. This use-after-free vulnerability occurs in the XSYNC fence triggering logic, specifically within the miSyncTriggerFence function. An attacker with access to the X11 server can exploit this without user interaction, leading to a server crash and potentially...

xorg: xwayland: X.Org X server: Denial of Service via integer underflow in XKB compatibility map handling

A flaw was found in the X.Org X server. This integer underflow vulnerability, specifically in the XKB compatibility map handling, allows an attacker with local or remote X11 server access to trigger a buffer read overrun. This can lead to memory-safety violations and potentially a denial of servi...

xorg: xwayland: X.Org X server: Use-after-free vulnerability leads to server crash and potential memory corruption

A flaw was found in the X.Org X server. This use-after-free vulnerability occurs in the XSYNC fence triggering logic, specifically within the miSyncTriggerFence function. An attacker with access to the X11 server can exploit this without user interaction, leading to a server crash and potentially...

xorg: xwayland: X.Org X server: Information exposure and denial of service via out-of-bounds memory access

A flaw was found in the X.Org X server's XKB key types request validation. A local attacker could send a specially crafted request to the X server, leading to an out-of-bounds memory access vulnerability. This could result in the disclosure of sensitive information or cause the server to crash,...

xorg: xwayland: X.Org X server: Denial of Service via integer underflow in XKB compatibility map handling

A flaw was found in the X.Org X server. This integer underflow vulnerability, specifically in the XKB compatibility map handling, allows an attacker with local or remote X11 server access to trigger a buffer read overrun. This can lead to memory-safety violations and potentially a denial of servi...

The vulnerability of the CheckKeyTypes() function in the XKB component of the Wayland protocol implementation for X.Org XWaylan, as well as in the X.Org Server implementation of the X Window System, allows a malicious actor to trigger a service failure.

The vulnerability of the CheckKeyTypes function in the XKB component of the Wayland protocol implementation for X.Org XWaylan, as well as in the X.Org Server implementation of the X Window System, is related to buffer overflow attacks. Exploiting this vulnerability can allow an attacker to cause ...