X.Org vulnerabilities
We track 61 vulnerabilities in X.Org products across 7 products. 61 are rated high or critical, and none are known to be exploited. The most recent was published on November 13, 2026.
Latest X.Org vulnerabilities
- 7.8 High severity
xwayland: Heap-based Buffer Overflow
A buffer overflow in handling EDID Display-Range descriptors in X.Org xwayland before 24.1.15 and X Server before 21.1.26 could be used by malicious monitors to crash the x server or execute cote.
- 8.5 High severity
xwayland: Integer Overflow or Wraparound
A integer overflow that can lead to a buffer overrread in the XRes QueryResourceBytes Swap Path in the X.Org xwayland before 24.1.15 and X Server before 21.1.26 on 32bit systems could be used by authenticated clients to crash the X server.
- 8.5 High severity
xwayland: Stack-based Buffer Overflow
A stack buffer overflow in ProcXTestFakeInput DeviceValuator handling in X.Org xwayland before 24.1.15 and X server before 21.1.26 could be used by authenticated clients to crash or execute code in the X server.
- 7.8 High severity
xwayland: Integer Underflow (Wrap or Wraparound)
Incorrectly handled negative sizes when processing ProcXvShmPutImage requests in the X.Org xwayland before 24.1.15 and X Server before 21.1.26 could be used by local authenticated X clients to crash the X server or execute code.
- 7.8 High severity
xwayland: Integer Underflow (Wrap or Wraparound)
A buffer overread caused by casting a negative integer to CARD32 in XvQueryImageAttributes in X.Org X Server before 21.1.26 and xwayland before 24.1.15 could be used to causes crashes by authenticated X clients.
- 7.8 High severity
xorg-x11-server: Heap-based Buffer Overflow
A heap buffer overflow caused by a XIPassiveUngrabDevice request with an out-of-range modifier value in X.Org X Server before 21.1.15 and XWayland before 24.1.14 could be used by authenticated X clients to crash or potentially execute code in X server context.
- 7.8 High severity
xorg-x11-server: Heap-based Buffer Overflow
A heap buffer overflow caused by mismatched size usage in CopyArea CPU-to-FBO path in X.Org X Server before 21.1.15 and XWayland before 24.1.14 could be used by authenticated X clients to crash or potentially execute code in the X server context.
- 7.8 High severity
xorg-x11-server: Heap-based Buffer Overflow
A buffer overflow in RandR ChangeProviderProperty requests in X.Org X Server before 2.1.25 and XWayland before 24.4.14 could be used by authenticated X clients to crash or execute code within the X server context.
- 7.8 High severity
xorg-x11-server: Heap-based Buffer Overflow
A heap buffer overflow caused by mismatching size calculations between XkbAllocNames and ChangeKeycodeRange in X.org X server before 2.1.25 and XWayland before 24.1.14 could be used by authenticated X clients to crash or potentially execute code in X server co
- 7.8 High severity
xorg-x11-server: Heap-based Buffer Overflow
A buffer overflow when handling pointer barriers in the XFIXES extension in X.Org X server before 21.1.25 and XWayland before 24.1.14 could be used by authenticated X clients to crash or potentially execute code in X server context.
- 7.8 High severity
xorg-x11-server: Heap-based Buffer Overflow
An integer truncation issue in XkbResizeKeyType() that could lead to a heap buffer overflow by authenticated X clients in X.org X server before 21.1.25 and XWayland before 24.1.14 could be exploited for crashes or potential code execution in the X server.
- 8.5 High severity
xorg-x11-server: Heap-based Buffer Overflow
A heap buffer overflow in handling GLX RenderLarge request where dataBytes exceeds cmdlen in X.org X server before 21.1.25 and XWayland before 24.1.14 that could be be triggered by an authenticated X client could cause crashes or code execution in X server con
- 7.8 High severity
xorg-x11-server: Double Free
A double free in XKB SetGeometryin X.Org X Server before 21.1.25 and X Wayland before 24.1.14 could be used by attached clients to cause a crash or potentially code in the x server context.
- 8.8 High severity
libXfont2: Heap-based Buffer Overflow
A heap buffer overflow due to missing size checking in the property buffer when parsing PCF files in libXfont2 ComputeScaledProperties() before libXfont2 before 2.0.8 could be used by attackers using authenticated X clients to execute code within the X server.
- 8.8 High severity
libXfont2: Heap-based Buffer Overflow
A heap bufferflow in pcfReadFont() due to missing glyph bounds checking in libXfont2 before 2.0.8 allows attackers authenticated as X client to execute code within the X server.
- 8.8 High severity
libXfont2: Heap-based Buffer Overflow
A heap buffer overflow in BitmapScaleBitmaps in libXfont2 before 2.0.8 due to an overflowing 32bit size could be used by attackers able to access the X Server to execute code within the X server cont
- 7.8 High severity
xorg-x11-server: Use After Free
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.
- 7.8 High severity
xorg-server: Heap-based 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.
- 7.8 High severity
Red Hat Enterprise Linux 10: Out-of-bounds Write
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 u
- 7.8 High severity
Red Hat Enterprise Linux 10: Use After Free
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. Thi
- 7.8 High severity
Red Hat Enterprise Linux 10: Use After Free
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 b
- 7.8 High severity
Red Hat Enterprise Linux 10: Stack-based Buffer Overflow
A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256] indexed by key type index. The helper function CheckKeyTypes() writes to this buffer at a client-controlled of
- 7.8 High severity
Red Hat Enterprise Linux 10: Stack-based Buffer Overflow
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
- 7.8 High severity
Red Hat Enterprise Linux 10: Use After Free
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
- 7.8 High severity
Red Hat Enterprise Linux 10: Stack-based Buffer Overflow
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 byt
- 9.1 Critical severity
Red Hat Enterprise Linux 10.0 Extended Update…: Buffer Access with Incorrect Length Value
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
- 9.1 Critical severity
Red Hat Enterprise Linux 10.0 Extended Update…: Out-of-bounds Read
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 atta
- 7.3 High severity
Xwayland: Use After Free
A flaw was discovered in the X.Org X server’s X Keyboard (Xkb) extension when handling client resource cleanup. The software frees certain data structures without properly detaching related resources, leading to a use-after-free condition. This can cause memor
- 7.3 High severity
Xwayland: Use After Free
A flaw was found in the X.Org X server and Xwayland when processing X11 Present extension notifications. Improper error handling during notification creation can leave dangling pointers that lead to a use-after-free condition. This can cause memory corruption
- 7.3 High severity
Xwayland: Integer Overflow or Wraparound
A flaw was identified in the X.Org X server’s X Keyboard (Xkb) extension where improper bounds checking in the XkbSetCompatMap() function can cause an unsigned short overflow. If an attacker sends specially crafted input data, the value calculation may overflo
- 7.8 High severity
xwayland: Integer Overflow or Wraparound
A flaw was found in the RandR extension, where the RRChangeProviderProperty function does not properly validate input. This issue leads to an integer overflow when computing the total size to allocate.
- 7.3 High severity
xwayland: Integer Overflow or Wraparound
A flaw was found in the X Record extension. The RecordSanityCheckRegisterClients function does not check for an integer overflow when computing request length, which allows a client to bypass length checks.
- 7.3 High severity
xwayland: Integer Overflow or Wraparound
A flaw was found in the Big Requests extension. The request length is multiplied by 4 before checking against the maximum allowed size, potentially causing an integer overflow and bypassing the size check.
- 7.7 High severity
X server: Improper Resource Locking
In X.Org X server 20.11 through 21.1.16, when a client application uses easystroke for mouse gestures, the main thread modifies various data structures used by the input thread without acquiring a lock, aka a race condition. In particular, AttachDevice in dix/
- 7.8 High severity
Red Hat Enterprise Linux 10: Use After Free
A use-after-free flaw was found in X.Org and Xwayland. When changing an alarm, the values of the change mask are evaluated one after the other, changing the trigger values as requested, and eventually, SyncInitTrigger() is called. If one of the changes trigger
- 7.8 High severity
Red Hat Enterprise Linux 10: Use After Free
A use-after-free flaw was found in X.Org and Xwayland. When a device is removed while still frozen, the events queued for that device remain while the device is freed. Replaying the events will cause a use-after-free.
- 7.8 High severity
Red Hat Enterprise Linux 10: Access of Uninitialized Pointer
An access to an uninitialized pointer flaw was found in X.Org and Xwayland. The function compCheckRedirect() may fail if it cannot allocate the backing pixmap. In that case, compRedirectWindow() will return a BadAlloc error without validating the window tree m
- 7.8 High severity
Red Hat Enterprise Linux 10: Out-of-bounds Write
An out-of-bounds write flaw was found in X.Org and Xwayland. The function GetBarrierDevice() searches for the pointer device based on its device ID and returns the matching value, or supposedly NULL, if no match was found. However, the code will return the las
- 7.8 High severity
Red Hat Enterprise Linux 10: Improper Restriction of Operations within the Bounds of a Memory Buffer
A buffer overflow flaw was found in X.Org and Xwayland. If XkbChangeTypesOfKey() is called with a 0 group, it will resize the key symbols table to 0 but leave the key actions unchanged. If the same function is later called with a non-zero value of groups, this
- 7.8 High severity
Red Hat Enterprise Linux 10: Out-of-bounds Write
A heap overflow flaw was found in X.Org and Xwayland. The computation of the length in XkbSizeKeySyms() differs from what is written in XkbWriteKeySyms(), which may lead to a heap-based buffer overflow.