X.org
X.org X Server: vulnerabilities and CVEs
X.org X Server has 106 published vulnerabilities, 19 of them in the last 12 months. 16 are rated critical and 0 are listed by CISA as actively exploited.
CVEs106
Last 12 months19
Critical16
Actively exploited0
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Latest vulnerabilities
| CVE | Severity | EPSS | Active exploitation | Published | Description |
|---|---|---|---|---|---|
| CVE-2026-56000 | Critical (9) | 0.31% | — | Jul 8, 2026 | 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… |
| CVE-2026-55999 | High (7.8) | 0.33% | — | Jul 8, 2026 | 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-2026-50264 | High (7.8) | 0.20% | — | Jun 5, 2026 | 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… |
| CVE-2026-50263 | Medium (5.5) | 0.19% | — | Jun 5, 2026 | A use-after-free flaw was found in the X.Org X server and Xwayland in CreateSaverWindow(). A client can trigger a use-after-free read after changing window attributes and forcing the screen saver, leading to information… |
| CVE-2026-50262 | Medium (5.5) | 0.18% | — | Jun 5, 2026 | An out-of-bounds read flaw was found in the X.Org X server and Xwayland in __glXDisp_ChangeDrawableAttributes(). A wrong size validation check can read a client-controlled number of bytes, exceeding the request buffer,… |
| CVE-2026-50261 | High (7.8) | 0.20% | — | Jun 5, 2026 | 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… |
| CVE-2026-50260 | High (7.8) | 0.20% | — | Jun 5, 2026 | 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… |
| CVE-2026-50259 | High (7.8) | 0.22% | — | Jun 5, 2026 | 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… |
| CVE-2026-50258 | High (7.8) | 0.22% | — | Jun 5, 2026 | 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… |
| CVE-2026-50257 | High (7.8) | 0.20% | — | Jun 5, 2026 | 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… |
| CVE-2026-50256 | High (7.8) | 0.21% | — | Jun 5, 2026 | 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… |
| CVE-2026-34002 | Critical (9.1) | 0.53% | — | May 5, 2026 | 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… |
| CVE-2026-34000 | Critical (9.1) | 0.53% | — | May 5, 2026 | 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… |
| CVE-2026-34003 | High (7.8) | 0.19% | — | Apr 23, 2026 | 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… |
| CVE-2026-34001 | High (7.8) | 0.19% | — | Apr 23, 2026 | 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… |
| CVE-2026-33999 | High (7.8) | 0.19% | — | Apr 23, 2026 | 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… |
| CVE-2025-62230 | High (7.3) | 0.28% | — | Oct 30, 2025 | 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… |
| CVE-2025-62229 | High (7.3) | 0.51% | — | Oct 30, 2025 | 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… |
| CVE-2025-62231 | High (7.3) | 0.30% | — | Oct 30, 2025 | 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… |
| CVE-2025-49178 | Medium (5.5) | 0.24% | — | Jun 17, 2025 | A flaw was found in the X server's request handling. Non-zero 'bytes to ignore' in a client's request can cause the server to skip processing another client's request, potentially leading to a denial of service. |
| CVE-2022-49737 | High (7.7) | 0.33% | — | Mar 16, 2025 | 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… |
| CVE-2025-26601 | High (7.8) | 0.39% | — | Feb 25, 2025 | 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()… |
| CVE-2025-26600 | High (7.8) | 0.39% | — | Feb 25, 2025 | 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. |
| CVE-2025-26599 | High (7.8) | 0.40% | — | Feb 25, 2025 | 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… |
| CVE-2025-26598 | High (7.8) | 0.40% | — | Feb 25, 2025 | 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… |
| CVE-2025-26597 | High (7.8) | 0.44% | — | Feb 25, 2025 | 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… |
| CVE-2025-26596 | High (7.8) | 0.44% | — | Feb 25, 2025 | 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. |
| CVE-2025-26595 | High (7.8) | 0.44% | — | Feb 25, 2025 | A buffer overflow flaw was found in X.Org and Xwayland. The code in XkbVModMaskText() allocates a fixed-sized buffer on the stack and copies the names of the virtual modifiers to that buffer. The code fails to check the… |
| CVE-2025-26594 | High (7.8) | 0.39% | — | Feb 25, 2025 | A use-after-free flaw was found in X.Org and Xwayland. The root cursor is referenced in the X server as a global variable. If a client frees the root cursor, the internal reference points to freed memory and causes a… |
| CVE-2024-31082 | High (7.3) | 0.34% | — | Apr 4, 2024 | A heap-based buffer over-read vulnerability was found in the X.org server's ProcAppleDRICreatePixmap() function. This issue occurs when byte-swapped length values are used in replies, potentially leading to memory… |