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,...

xwayland: xorg: X.Org X server: Information disclosure and denial of service via out-of-bounds read in XKB geometry processing.

A flaw was found in the X.Org X server. This out-of-bounds read vulnerability in the XKB geometry processing, specifically within the CheckSetGeom and XkbAddGeomKeyAlias functions, allows an attacker to read uninitialized or out-of-bounds memory. An attacker with a connection to the X11 server,...

Important: xorg-x11-server-Xwayland

Issue Overview: A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. A mismatch between the X server and the libXfont2 library's maximum font name length can cause a stack buffer overflow during font alias resolution. The server allocates a 256 byte stack buffer but...

TencentOS Server 4: xorg-x11-server (TSSA-2026:0294)

The version of Tencent Linux installed on the remote TencentOS Server 4 host is prior to tested version. It is, therefore, affected by multiple vulnerabilities as referenced in the TSSA-2026:0294 advisory. Package updates are available for TencentOS Server 4 that fix the following vulnerabilities...

TencentOS Server 4: xorg-x11-server-Xwayland (TSSA-2026:0402)

The version of Tencent Linux installed on the remote TencentOS Server 4 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the TSSA-2026:0402 advisory. Package updates are available for TencentOS Server 4 that fix the following vulnerabilities:...

Important: xorg-x11-server

Issue Overview: A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. A mismatch between the X server and the libXfont2 library's maximum font name length can cause a stack buffer overflow during font alias resolution. The server allocates a 256 byte stack buffer but...

Important: xorg-x11-server

Issue Overview: A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. A mismatch between the X server and the libXfont2 library's maximum font name length can cause a stack buffer overflow during font alias resolution. The server allocates a 256 byte stack buffer but...

TencentOS Server 4: tigervnc (TSSA-2026:0412)

The version of Tencent Linux installed on the remote TencentOS Server 4 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the TSSA-2026:0412 advisory. Package updates are available for TencentOS Server 4 that fix the following vulnerabilities:...

TencentOS Server 4: xorg-x11-server (TSSA-2026:0399)

The version of Tencent Linux installed on the remote TencentOS Server 4 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the TSSA-2026:0399 advisory. Package updates are available for TencentOS Server 4 that fix the following vulnerabilities:...

RHEL 8 : tigervnc (RHSA-2026:23254)

The remote Redhat Enterprise Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:23254 advisory. Virtual Network Computing VNC is a remote display system which allows users to view a computing desktop environment not only on the machine...

RHEL 8 : tigervnc (RHSA-2026:23255)

The remote Redhat Enterprise Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:23255 advisory. Virtual Network Computing VNC is a remote display system which allows users to view a computing desktop environment not only on the machine...

RHEL 6 : tigervnc (RHSA-2026:23496)

The remote Redhat Enterprise Linux 6 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:23496 advisory. Virtual Network Computing VNC is a remote display system which allows users to view a computing desktop environment not only on the machine...

CVE-2026-50259 Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: stack buffer overflow in xkb setmap request via mapwidths indexing

A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. XkbSetMapChecks declares a fixed-size stack buffer mapWidths256 indexed by key type index. The helper function CheckKeyTypes writes to this buffer at a client-controlled offset, allowing a stack buffer overflow. This...

CVE-2026-50259

The CVE-2026-50259 entry describes a stack-based buffer overflow in X.Org X server and Xwayland. The vulnerability centers on XkbSetMapChecks(), which declares a fixed-size buffer mapWidths[256] on the stack and is indexed by key type. CheckKeyTypes() writes to this buffer at a client-controlled ...

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: Information disclosure or Denial of Service via out-of-bounds read in XKB modifier map handling

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: 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...

xwayland: xorg: X.Org X server: Information disclosure and denial of service via out-of-bounds read in XKB geometry processing.

A flaw was found in the X.Org X server. This out-of-bounds read vulnerability in the XKB geometry processing, specifically within the CheckSetGeom and XkbAddGeomKeyAlias functions, allows an attacker to read uninitialized or out-of-bounds memory. An attacker with a connection to the X11 server,...

xorg: xwayland: X.Org X server: Information disclosure or Denial of Service via out-of-bounds read in XKB modifier map handling

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...

Important: Red Hat Security Advisory: tigervnc security update

An update for tigervnc is now available for Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support and Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On. Red Hat Product Security has rated this update as having a security impact of Important. A Common...