CVE-2026-34003
HighCVSS 7.8Exploitation Probability (EPSS)
Low risk16th percentile - higher than 16% of all known CVEs
Summary
A flaw was found in the X.Org X server's XKB key types request validation. A local attacker can send a specially crafted request, causing an out-of-bounds memory access.
Risk Assessment
This vulnerability may lead to disclosure of sensitive information or crash the X server, resulting in Denial of Service (DoS). In certain configurations, more severe impacts are possible.
Recommendation
Immediately update the X.Org X server to the latest patched version. Restricting access to the X server to trusted users reduces the risk.
Other vulnerabilities in X.Org X server
See all- CVE-2026-93516Medium
A use-after-free caused by lack of lifecycle management when adding or removing XInput master devices exists in X.org X Server before 21.1.25 and XWayland before 24.1.14. An authenticated X client could exploit this to crash the X server or potentially execute code in the X server context.
- CVE-2026-93515Medium
A use-after-free in present_clear_window_notifies() in X.org X Server before 21.1.25 and XWayland before 24.1.14 could be exploited by malicious X clients to crash the server or potentially execute code in the X server context.
- CVE-2017-10971High
In the X.Org X server before 2017-06-19, a user authenticated to an X Session could crash or execute code in the context of the X Server by exploiting a stack overflow in the endianness conversion of X Events.
- CVE-2026-93536Medium
A use-after-free caused by missing lifecycle management of gesture sprites in GestureBuildSprite() exists in X.Org X Server before 21.1.25 and XWayland before 24.1.14. An authenticated X client could exploit it to crash the X server or potentially execute code.
- CVE-2026-93524Medium
A buffer overread in CheckKeySyms() exists in X.Org X Server before 21.1.25 and XWayland before 24.1.14. An authenticated X client could exploit it to leak small amounts of information from X server memory or potentially crash the X server.
- CVE-2026-93523High
A heap buffer overflow in X.Org X Server before 21.1.15 and XWayland before 24.1.14 is triggered by an XIPassiveUngrabDevice request with an out-of-range modifier value. An authenticated X client could exploit this to crash the X server or potentially execute code in the server context.
- CVE-2026-93522High
A heap buffer overflow caused by mismatched size usage in the CopyArea CPU-to-FBO path in X.Org X Server before 21.1.15 and XWayland before 24.1.14. Authenticated X clients could use it to crash the server or potentially execute code in the X server context.
- CVE-2026-93521High
A buffer overflow in RandR ChangeProviderProperty requests in X.Org X Server before 2.1.25 and XWayland before 24.4.14. Authenticated X clients could use it to crash the server or execute code within the X server context.
- CVE-2026-93520High
A heap buffer overflow caused by mismatching size calculations between XkbAllocNames and ChangeKeycodeRange exists in X.org X server before 2.1.25 and XWayland before 24.1.14. Authenticated X clients could exploit it to crash or potentially execute code in the X server context.
- CVE-2026-93519High
A buffer overflow when handling pointer barriers in the XFIXES extension exists in X.Org X server before 21.1.25 and XWayland before 24.1.14. Authenticated X clients could exploit it to crash or potentially execute code in the X server context.
Original NVD description (English source)
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, leading to a Denial of Service (DoS). In certain configurations, higher impact outcomes may be possible.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

