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

An update for xorg-x11-server 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...

xorg: X11: xserver: X.org: glamor Font Atlas Heap Buffer Overflow

A flaw was found in the glamorfontget function of the xorg-x11-server. This vulnerability, a heap buffer overflow, occurs when the server processes a specially crafted PCF font file where individual glyph metrics exceed the declared maximum bounds. An authenticated X client can exploit this by...

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

An update for xorg-x11-server is now available for Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support and Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On. Red Hat Product Security has rated this update as having a security impact of Important. A Common...

xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free in miSyncDestroyFence()

A use-after-free flaw was found in the X.Org X server and Xwayland in miSyncDestroyFence. A client that sets up multiple fence triggers can trigger a use-after-free function pointer call. An attacker would connect to the X server to set up a fence and await that fence, then a second X connection...

xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: out-of-bounds read/write in GLX ChangeDrawableAttributes

An out-of-bounds read flaw was found in the X.Org X server and Xwayland in glXDispChangeDrawableAttributes. A wrong size validation check can read a client-controlled number of bytes, exceeding the request buffer, leading to information disclosure. A write path also exists but requires byte-swapp...

Important: Red Hat Security Advisory: tigervnc security update

An update for tigervnc is now available for Red Hat Enterprise Linux 6 Extended Lifecycle Support - EXTENSION. 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 severity rating, is...

MiracleLinux 9 : tigervnc-1.15.0-7.el9_8.2 (AXSA:2026-1425:07)

The remote MiracleLinux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the AXSA:2026-1425:07 advisory. xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: stack buffer overflow in font alias resolution due to libXfont2 name length mismatch...

Updated x11-server x11-server-xwayland tigervnc packages fix security vulnerabilities

The updated packages fix security vulnerabilities: glamor Font Atlas Heap Buffer Overflow. CVE-2026-55999 GLX contextTags Use-After-Free in CommonMakeCurrent. CVE-2026-56000...

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...

xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: out-of-bounds read/write in GLX ChangeDrawableAttributes

An out-of-bounds read flaw was found in the X.Org X server and Xwayland in glXDispChangeDrawableAttributes. A wrong size validation check can read a client-controlled number of bytes, exceeding the request buffer, leading to information disclosure. A write path also exists but requires byte-swapp...

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...

Important: Red Hat Security Advisory: tigervnc security update

An update for tigervnc 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 severity rating, is...

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...

RHEL 7 : tigervnc (RHSA-2026:46473)

The remote Redhat Enterprise Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:46473 advisory. Virtual Network Computing VNC is a remote display system which allows users to view a computing desktop environment not only on the machine...

MiracleLinux 9 : xorg-x11-server-Xwayland-24.1.9-4.el9_8.2 (AXSA:2026-1355:07)

The remote MiracleLinux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the AXSA:2026-1355:07 advisory. xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: stack buffer overflow in font alias resolution due to libXfont2 name length mismatch...

MiracleLinux 9 : xorg-x11-server-1.20.11-34.el9_8.2 (AXSA:2026-1354:12)

The remote MiracleLinux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the AXSA:2026-1354:12 advisory. xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: stack buffer overflow in font alias resolution due to libXfont2 name length mismatch...

RHEL 8 : tigervnc (RHSA-2026:46385)

The remote Redhat Enterprise Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:46385 advisory. Virtual Network Computing VNC is a remote display system which allows users to view a computing desktop environment not only on the machine...

Amazon Linux 2 : xorg-x11-server, --advisory ALAS2-2026-3806 (ALAS-2026-3806)

It is, therefore, affected by a vulnerability as referenced in the ALAS2-2026-3806 advisory. glamor Font Atlas Heap Buffer Overflow CVE-2026-55999 Tenable has extracted the preceding description block directly from the tested product security advisory. Note that Nessus has not tested for this iss...

Amazon Linux 2023 : xorg-x11-server-Xwayland, xorg-x11-server-Xwayland-devel (ALAS2023-2026-1944)

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2026-1944 advisory. glamor Font Atlas Heap Buffer Overflow CVE-2026-55999 GLX contextTags Use-After-Free in CommonMakeCurrent CVE-2026-56000 Tenable has extracted the preceding description block directly from the...

Important: xorg-x11-server

Issue Overview: glamor Font Atlas Heap Buffer Overflow CVE-2026-55999 Affected Packages: xorg-x11-server Issue Correction: Run dnf update xorg-x11-server --releasever 2023.12.20260720 or dnf update --advisory ALAS2023-2026-1943 --releasever 2023.12.20260720 to update your system. More information...