Threat Intelligence Database

Two security vulnerabilities affecting xorg-x11-server-Xwayland in Red Hat Enterprise Linux 10 have been addressed. These include a heap buffer overflow in the glamor Font Atlas component (CVE-2026-55999) and a use-after-free vulnerability in GLX contextTags within CommonMakeCurrent() (CVE-2026-56000). Both issues are rated with high severity by Red Hat Product Security. An update is available to remediate these vulnerabilities.

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 enabling memory corruption. This could result in a denial of service or further compromise of the system.

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 service (DoS) or other severe impacts.

Xwayland is an X server for running X clients under Wayland. Security Fix(es): * xorg: xmayland: Use-after-free in XPresentNotify structure creation (CVE-2025-62229) * xorg: xwayland: Use-after-free in Xkb client resource removal (CVE-2025-62230) * xorg: xmayland: Value overflow in XkbSetCompatMap() (CVE-2025-62231) 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.

Xwayland is an X server for running X clients under Wayland. Security Fix(es): * xorg: xmayland: Use-after-free in XPresentNotify structure creation (CVE-2025-62229) * xorg: xwayland: Use-after-free in Xkb client resource removal (CVE-2025-62230) * xorg: xmayland: Value overflow in XkbSetCompatMap() (CVE-2025-62231) 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.

Multiple use-after-free and value overflow vulnerabilities have been identified in the xorg-x11-server-Xwayland component affecting Red Hat Enterprise Linux 9 and related variants. These vulnerabilities have been assigned CVE identifiers CVE-2025-62229, CVE-2025-62230, and CVE-2025-62231. The issues involve improper memory handling in XPresentNotify structure creation, Xkb client resource removal, and XkbSetCompatMap() function. A security update has been released by Red Hat to address these vulnerabilities. The severity is rated as medium, and no known exploits are currently reported in the wild.

Xwayland is an X server for running X clients under Wayland. Security Fix(es): * xorg: xmayland: Use-after-free in XPresentNotify structure creation (CVE-2025-62229) * xorg: xwayland: Use-after-free in Xkb client resource removal (CVE-2025-62230) * xorg: xmayland: Value overflow in XkbSetCompatMap() (CVE-2025-62231) 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.

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-Xwayland: xorg-x11-server: tigervnc: Out-of-Bounds Read in X Rendering Extension Animated Cursors (CVE-2025-49175) * xorg-x11-server-Xwayland: xorg-x11-server: tigervnc: Integer Overflow in Big Requests Extension (CVE-2025-49176) * xorg-x11-server-Xwayland: xorg-x11-server: tigervnc: Unprocessed Client Request Due to Bytes to Ignore (CVE-2025-49178) * xorg-x11-server-Xwayland: xorg-x11-server: tigervnc: Integer overflow in X Record extension (CVE-2025-49179) * xorg-x11-server-Xwayland: xorg-x11-server: tigervnc: Integer Overflow in X Resize, Rotate and Reflect (RandR) Extension (CVE-2025-49180) 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.

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-Xwayland: xorg-x11-server: tigervnc: Out-of-Bounds Read in X Rendering Extension Animated Cursors (CVE-2025-49175) * xorg-x11-server-Xwayland: xorg-x11-server: tigervnc: Integer Overflow in Big Requests Extension (CVE-2025-49176) * xorg-x11-server-Xwayland: xorg-x11-server: tigervnc: Unprocessed Client Request Due to Bytes to Ignore (CVE-2025-49178) * xorg-x11-server-Xwayland: xorg-x11-server: tigervnc: Integer overflow in X Record extension (CVE-2025-49179) * xorg-x11-server-Xwayland: xorg-x11-server: tigervnc: Integer Overflow in X Resize, Rotate and Reflect (RandR) Extension (CVE-2025-49180) 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.

Xwayland is an X server for running X clients under Wayland. Security Fix(es): * xorg-x11-server-Xwayland: xorg-x11-server: tigervnc: Out-of-Bounds Read in X Rendering Extension Animated Cursors (CVE-2025-49175) * xorg-x11-server-Xwayland: xorg-x11-server: tigervnc: Integer Overflow in Big Requests Extension (CVE-2025-49176) * xorg-x11-server-Xwayland: xorg-x11-server: tigervnc: Data Leak in XFIXES Extension's XFixesSetClientDisconnectMode (CVE-2025-49177) * xorg-x11-server-Xwayland: xorg-x11-server: tigervnc: Unprocessed Client Request Due to Bytes to Ignore (CVE-2025-49178) * xorg-x11-server-Xwayland: xorg-x11-server: tigervnc: Integer overflow in X Record extension (CVE-2025-49179) * xorg-x11-server-Xwayland: xorg-x11-server: tigervnc: Integer Overflow in X Resize, Rotate and Reflect (RandR) Extension (CVE-2025-49180) 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.