# X.Org Foundation X.Org Server vulnerabilities Source: https://junglewise.ai/threats/technologies/x-server Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats Updated: 9 November 2026, 03:07 UTC. Rebuilt every hour. Data: https://junglewise.ai/threats/technologies/x-server.json License: CC BY 4.0 with a link back Junglewise Threat Intelligence has tracked 10 vulnerabilities in X.Org Foundation X.Org Server: 0 in the last 7 days and 1 in the last 90 days, 1 of them critical and 0 exploited in the wild. The most recent, CVE-2026-88812, was published on 27 October 2026. 1 vulnerability in the last four weeks, up from none in the four before. ## Counts - Last 7 days: 0 - Last 30 days: 1 - Last 90 days: 1 - All time: 10 (1 critical, 0 exploited in the wild) ## About X.Org Foundation X.Org Server The X.Org Server is the free and open-source implementation of the X Window System display server. ## Latest X.Org Foundation X.Org Server vulnerabilities - [CVE-2026-88812: X.Org X Server double free in XKB SetGeometry](https://junglewise.ai/threats/cve-2026-88812-a-double-free-in-xkb-setgeometryin-x-org-x-server-before-21-1-25) (high, CVSS 7.8, published 27 Oct 2026) - [CVE-2026-50264: X.Org X server and Xwayland out-of-bounds write in DRI2](https://junglewise.ai/threats/cve-2026-50264-x-org-x-server-and-xwayland-out-of-bounds-write-in-dri2) (high, CVSS 7.8, published 5 Jun 2026) - [CVE-2026-50261: X.Org X server use-after-free in SyncChangeCounter](https://junglewise.ai/threats/cve-2026-50261-x-org-x-server-use-after-free-in-syncchangecounter) (high, CVSS 7.8, published 5 Jun 2026) - [CVE-2026-50260: X.Org X server and Xwayland use-after-free in FreeCounter](https://junglewise.ai/threats/cve-2026-50260-x-org-x-server-and-xwayland-use-after-free-in-freecounter) (high, CVSS 7.8, published 5 Jun 2026) - [CVE-2026-50259: X.Org X server stack buffer overflow in XKB SetMap request](https://junglewise.ai/threats/cve-2026-50259-x-org-x-server-stack-buffer-overflow-in-xkb-setmap-request) (high, CVSS 7.8, published 5 Jun 2026) - [CVE-2026-34003: X.Org X server out-of-bounds memory access in XKB request validation](https://junglewise.ai/threats/cve-2026-34003-x-org-x-server-out-of-bounds-memory-access-in-xkb-request) (high, CVSS 7.8, published 23 Apr 2026) - [CVE-2026-34001: X.Org X server use-after-free in miSyncTriggerFence](https://junglewise.ai/threats/cve-2026-34001-x-org-x-server-use-after-free-in-misynctriggerfence) (high, CVSS 7.8, published 23 Apr 2026) - [CVE-2026-33999: X.Org X server integer underflow in XKB compatibility map handling](https://junglewise.ai/threats/cve-2026-33999-x-org-x-server-integer-underflow-in-xkb-compatibility-map) (high, CVSS 7.8, published 23 Apr 2026) - [CVE-2025-62230: X.Org X server use-after-free in Xkb client resource removal](https://junglewise.ai/threats/cve-2025-62230-x-org-x-server-use-after-free-in-xkb-client-resource-removal) (high, CVSS 7.3, published 30 Oct 2025) - [CVE-1999-0526: X.Org X Server access control bypass via insecure xhost configuration](https://junglewise.ai/threats/cve-1999-0526-x-org-x-server-access-control-bypass-via-insecure-xhost) (critical, CVSS 10, published 1 Jul 1997) ## Most severe X.Org Foundation X.Org Server vulnerabilities - [CVE-1999-0526: X.Org X Server access control bypass via insecure xhost configuration](https://junglewise.ai/threats/cve-1999-0526-x-org-x-server-access-control-bypass-via-insecure-xhost) (critical, CVSS 10, published 1 Jul 1997) - [CVE-2026-34003: X.Org X server out-of-bounds memory access in XKB request validation](https://junglewise.ai/threats/cve-2026-34003-x-org-x-server-out-of-bounds-memory-access-in-xkb-request) (high, CVSS 7.8, published 23 Apr 2026) - [CVE-2026-34001: X.Org X server use-after-free in miSyncTriggerFence](https://junglewise.ai/threats/cve-2026-34001-x-org-x-server-use-after-free-in-misynctriggerfence) (high, CVSS 7.8, published 23 Apr 2026) - [CVE-2026-33999: X.Org X server integer underflow in XKB compatibility map handling](https://junglewise.ai/threats/cve-2026-33999-x-org-x-server-integer-underflow-in-xkb-compatibility-map) (high, CVSS 7.8, published 23 Apr 2026) - [CVE-2026-88812: X.Org X Server double free in XKB SetGeometry](https://junglewise.ai/threats/cve-2026-88812-a-double-free-in-xkb-setgeometryin-x-org-x-server-before-21-1-25) (high, CVSS 7.8, published 27 Oct 2026) - [CVE-2026-50264: X.Org X server and Xwayland out-of-bounds write in DRI2](https://junglewise.ai/threats/cve-2026-50264-x-org-x-server-and-xwayland-out-of-bounds-write-in-dri2) (high, CVSS 7.8, published 5 Jun 2026) - [CVE-2026-50261: X.Org X server use-after-free in SyncChangeCounter](https://junglewise.ai/threats/cve-2026-50261-x-org-x-server-use-after-free-in-syncchangecounter) (high, CVSS 7.8, published 5 Jun 2026) - [CVE-2026-50260: X.Org X server and Xwayland use-after-free in FreeCounter](https://junglewise.ai/threats/cve-2026-50260-x-org-x-server-and-xwayland-use-after-free-in-freecounter) (high, CVSS 7.8, published 5 Jun 2026) - [CVE-2026-50259: X.Org X server stack buffer overflow in XKB SetMap request](https://junglewise.ai/threats/cve-2026-50259-x-org-x-server-stack-buffer-overflow-in-xkb-setmap-request) (high, CVSS 7.8, published 5 Jun 2026) - [CVE-2025-62230: X.Org X server use-after-free in Xkb client resource removal](https://junglewise.ai/threats/cve-2025-62230-x-org-x-server-use-after-free-in-xkb-client-resource-removal) (high, CVSS 7.3, published 30 Oct 2025) ## Vulnerabilities per week 1 vulnerability in the last four weeks, up from none in the four before. | Week of | Vulns | Critical | Exploited | | --- | --- | --- | --- | | 17 Aug 2026 | 0 | 0 | 0 | | 24 Aug 2026 | 0 | 0 | 0 | | 31 Aug 2026 | 0 | 0 | 0 | | 7 Sep 2026 | 0 | 0 | 0 | | 14 Sep 2026 | 0 | 0 | 0 | | 21 Sep 2026 | 0 | 0 | 0 | | 28 Sep 2026 | 0 | 0 | 0 | | 5 Oct 2026 | 0 | 0 | 0 | | 12 Oct 2026 | 0 | 0 | 0 | | 19 Oct 2026 | 0 | 0 | 0 | | 26 Oct 2026 | 1 | 0 | 0 | | 2 Nov 2026 | 0 | 0 | 0 | | 9 Nov 2026 | 0 | 0 | 0 | ## Other X.Org Foundation technologies - [X.Org Foundation Xwayland](https://junglewise.ai/threats/technologies/xwayland): 6 vulnerabilities ## Sources NVD, GitHub Security Advisories, OSV, the CISA Known Exploited Vulnerabilities catalog, FIRST EPSS and vendor advisories. Rebuilt every hour. Cite as: Junglewise Threat Intelligence, "X.Org Foundation X.Org Server vulnerabilities", https://junglewise.ai/threats/technologies/x-server, 9 November 2026.