xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: stack buffer overflow in font alias resolution due to libXfont2 name length mismatch

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 libXfont2's alias...

xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: out-of-bounds heap write in DRI2 DRIGetBuffers/DRIGetBuffersWithFormat

An out-of-bounds write flaw was found in the X.Org X server and Xwayland in DRIGetBuffers/DRIGetBuffersWithFormat. A client that requests multiple DRI2BufferBackLeft attachments and one DRI2BufferFrontLeft can trigger an out-of-bounds heap write. This may be used to crash the server, or for...

xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: stack buffer overflow in XKB key types due to unchecked shift levels

A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. The X server has multiple stack buffers sized XkbMaxShiftLevel XkbNumKbdGroups but CheckKeyTypes does not verify or clamp non-canonical key types to XkbMaxShiftLevel. A client can change key types to excessive shift...

Important: Red Hat Security Advisory: xorg-x11-server-Xwayland security update

An update for xorg-x11-server-Xwayland is now available for Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System CVSS base score, which gives a detailed severi...

CVE-2026-56000

Local attackers with a X connection able to provide GLX commit to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a Heap Use After Free, due to CommonMakeCurrent pointing into potentially reallocated memory...

CVE-2026-56000

Local attackers with a X connection able to provide GLX commit to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a Heap Use After Free, due to CommonMakeCurrent pointing into potentially reallocated memory...

EUVD-2026-42188

Local attackers with a X connection able to provide PCX fonts to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a heap buffer overflow via SetFont due to missing glyph boundary checks...

CVE-2026-55999

CVE-2026-55999 affects xorg-server (before 21.2.24) and xwayland (before 24.1.13). A local attacker with a X connection can trigger a heap buffer overflow in glamor font atlas via SetFont due to missing glyph boundary checks. Impact is a potential heap corruption, with high likelihood of exploita...

CVE-2026-55999 xorg-server / xwayland glamor font atlas Heap Buffer Overflow

Local attackers with a X connection able to provide PCX fonts to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a heap buffer overflow via SetFont due to missing glyph boundary checks...

CVE-2026-55999 xorg-server / xwayland glamor font atlas Heap Buffer Overflow

Local attackers with a X connection able to provide PCX fonts to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a heap buffer overflow via SetFont due to missing glyph boundary checks...

CVE-2026-55999 xorg-server / xwayland glamor font atlas Heap Buffer Overflow

Local attackers with a X connection able to provide PCX fonts to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a heap buffer overflow via SetFont due to missing glyph boundary checks...

Security update for xorg-x11-server

This update for xorg-x11-server fixes the following issue CVE-2026-55999: missing bounds check in glamorfontget can lead to a heap buffer overflow when a font loaded from a malicious PCF file is processed bsc1268893. Patch Instructions: To install this SUSE update use the SUSE recommended...

CVE-2026-56000

Local attackers with a X connection able to provide GLX commit to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a Heap Use After Free, due to CommonMakeCurrent pointing into potentially reallocated memory...

CVE-2026-56000

CVE-2026-56000 affects the X.org X server stack: specifically xorg-x11-server and xwayland. A Use-After-Free in CommonMakeCurrent() exposes heap corruption when GLX commit data is processed over an X connection, due to a pointer into memory that may be reallocated. Impact is described as local/pr...

EUVD-2026-42202

Local attackers with a X connection able to provide GLX commit to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a Heap Use After Free, due to CommonMakeCurrent pointing into potentially reallocated memory...

Security update for xorg-x11-server

This update for xorg-x11-server fixes the following issues CVE-2026-55999: missing bounds check in glamorfontget can lead to a heap buffer overflow when a font loaded from a malicious PCF file is processed bsc1268893. CVE-2026-56000: improper memory management in CommonMakeCurrent can lead to a...

SUSE-SU-2026:2788-1 Security update for xorg-x11-server

This update for xorg-x11-server fixes the following issues - CVE-2026-55999: missing bounds check in glamorfontget can lead to a heap buffer overflow when a font loaded from a malicious PCF file is processed bsc1268893. - CVE-2026-56000: improper memory management in CommonMakeCurrent can lead to...

Amazon Linux 2 : tigervnc, --advisory ALAS2-2026-3792 (ALAS-2026-3792)

The version of tigervnc installed on the remote host is prior to 1.8.0-24. It is, therefore, affected by a vulnerability as referenced in the ALAS2-2026-3792 advisory. A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. XkbSetMapChecks declares a fixed-size stack buff...

PT-2026-56335

Name of the Vulnerable Software and Affected Versions xorg-server versions prior to 21.2.24 xwayland versions prior to 24.1.13 Description Local attackers with an X connection can cause a Heap Use After Free, a condition where the system continues to use a memory address after it has been freed,...

Linux Distros Unpatched Vulnerability : CVE-2026-55999

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - Local attackers with a X connection able to provide PCX fonts to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a heap buffer...