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: 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: 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...

The vulnerability of the miSyncDestroyFence() function in the Wayland protocol for X.Org XWaylan, as well as in the X.Org Server, allows a malicious actor to escalate their privileges and cause service failures.

The vulnerability of the miSyncDestroyFence function in the Wayland protocol for X.Org XWaylan, as well as in the X.Org Server, is related to the possibility of using memory after it is freed. Exploiting this vulnerability can allow a malicious actor to increase their privileges and cause service...

The vulnerability of the CheckKeyTypes() function in 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 escalate their privileges and cause service failures.

The vulnerability of the CheckKeyTypes function in the Wayland protocol for X.Org XWaylan, as well as in the X.Org Server, is related to the execution of operations outside of the buffer in memory. Exploiting this vulnerability can allow attackers to gain increased privileges and cause service...

X.Org Server CheckSetGeom Out-Of-Bounds Read Information Disclosure Vulnerability

This vulnerability allows local attackers to disclose sensitive information on affected installations of X.Org Server. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the handling...

X.Org Server XkbSetCompatMap Integer Underflow Privilege Escalation Vulnerability

This vulnerability allows local attackers to escalate privileges on affected installations of X.Org Server. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the handling of...

X.Org Server CheckKeyTypes Buffer Overflow Privilege Escalation Vulnerability

This vulnerability allows local attackers to escalate privileges on affected installations of X.Org Server. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the handling of key...

CVE-2026-50259

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-2026-50262

CVE-2026-50262 affects the X.Org X server and Xwayland where __glXDisp_ChangeDrawableAttributes() contains a faulty size check that can allow an out-of-bounds read of a client-controlled byte count, potentially leading to information disclosure. A write path exists but requires byte-swapped clien...

CVE-2026-50261

A use-after-free flaw was found in the X.Org X server and Xwayland in SyncChangeCounter. A client that sets up multiple SyncCounters can trigger a use-after-free when destroying those counters via a second client connection while changing those counters. This may be used to crash the server, or f...

CVE-2026-50260 Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: use-after-free in freecounter()

A use-after-free flaw was found in the X.Org X server and Xwayland in FreeCounter. A client that sets up multiple SyncCounters and awaits on those triggers can trigger a use-after-free when destroying those counters via a second client connection. This may be used to crash the server, or for...

CVE-2026-50259

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-2026-50256

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...

X.Org Server 缓冲区错误漏洞

X.Org is open-source free software developed by the X.Org Foundation. Xwayland is an open-source communication protocol developed by Xwayland that defines how communication between display servers and clients occurs. There are buffer overflow vulnerabilities in the X.Org X server and Xwayland,...

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: 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...

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...

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,...