# CVE-2026-56000: xorg-x11-server / xwayland GLX contextTags Use-After-Free in CommonMakeCurrent()

CVE-2026-56000 is fixed in 7 products on 1 platform, first by SUSE-SU-2026:2786-1, released July 8, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-56000
- Priority: High
- CVSS: 7.8 (Moderate)
- EPSS: 0.0031
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 8, 2026
- Weakness: Use After Free
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56000

## Description

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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | xorg-server Debian 13.5 (trixie) | 2:21.1.16-1.3+deb13u4 | [DEBIAN-CVE-2026-56000](https://patchblox.com/security/data/fix/linux/debian-cve-2026-56000.md) | Jul 8, 2026 |
| Linux | xorg-server Debian 14 | 2:21.1.24-1 | [DEBIAN-CVE-2026-56000](https://patchblox.com/security/data/fix/linux/debian-cve-2026-56000.md) | Jul 8, 2026 |
| Linux | xorg-x11-server opensuse-leap 16.0 | 21.1.15-160000.6.1 | [OPENSUSE-SU-2026:21273-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21273-1.md) | Jul 8, 2026 |
| Linux | xorg-x11-server sles 15.6 | 21.1.11-150600.5.31.1 | [SUSE-SU-2026:2786-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2786-1.md) | Jul 8, 2026 |
| Linux | xorg-x11-server sles 15.7 | 21.1.15-150700.5.22.1 | [SUSE-SU-2026:2788-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2788-1.md) | Jul 8, 2026 |
| Linux | xorg-x11-server-Xwayland RHEL 10 | 24.1.5-6.el10_0.2 | [RHSA-2026:50100](https://patchblox.com/security/data/fix/linux/rhsa-2026-50100.md) | Jul 13, 2026 |
| Linux | xorg-x11-server-Xwayland RHEL 9 | 0:24.1.9-4.el9_8.3 | [RHSA-2026:38490](https://patchblox.com/security/data/fix/linux/rhsa-2026-38490.md) | Jul 13, 2026 |
| Linux | xorg-x11-server-Xwayland almalinux 10 | 24.1.9-4.el10_2.3 | [ALSA-2026:38489](https://patchblox.com/security/data/fix/linux/alsa-2026-38489.md) | Jul 13, 2026 |
| Linux | xorg-x11-server-Xwayland almalinux 9 | 24.1.9-4.el9_8.3 | [ALSA-2026:38490](https://patchblox.com/security/data/fix/linux/alsa-2026-38490.md) | Jul 13, 2026 |
| Linux | xorg-x11-server-Xwayland amzn 2023 | 24.1.3-1.amzn2023.0.6 | [ALAS2023-2026-1944](https://patchblox.com/security/data/fix/linux/alas2023-2026-1944.md) | Jul 20, 2026 |
| Linux | xorg-x11-server-Xwayland ol 10 | 0:24.1.9-4.el10_2.3 | [ELSA-2026-38489](https://patchblox.com/security/data/fix/linux/elsa-2026-38489.md) | Sep 1, 2026 |
| Linux | xorg-x11-server-Xwayland ol 9 | 0:24.1.9-4.el9_8.3 | [ELSA-2026-38490](https://patchblox.com/security/data/fix/linux/elsa-2026-38490.md) | Sep 1, 2026 |
| Linux | xorg-x11-server-Xwayland rocky 10 | 0:24.1.9-4.el10_2.3 | [RLSA-2026:38489](https://patchblox.com/security/data/fix/linux/rlsa-2026-38489.md) | Jul 14, 2026 |
| Linux | xorg-x11-server-Xwayland rocky 9 | 0:24.1.9-4.el9_8.3 | [RLSA-2026:38490](https://patchblox.com/security/data/fix/linux/rlsa-2026-38490.md) | Jul 14, 2026 |
| Linux | xorg-x11-server-Xwayland-debuginfo amzn 2023 | 24.1.3-1.amzn2023.0.6 | [ALAS2023-2026-1944](https://patchblox.com/security/data/fix/linux/alas2023-2026-1944.md) | Jul 20, 2026 |
| Linux | xorg-x11-server-Xwayland-debugsource amzn 2023 | 24.1.3-1.amzn2023.0.6 | [ALAS2023-2026-1944](https://patchblox.com/security/data/fix/linux/alas2023-2026-1944.md) | Jul 20, 2026 |
| Linux | xorg-x11-server-Xwayland-devel RHEL 9 | 0:24.1.9-4.el9_8.3 | [RHSA-2026:38490](https://patchblox.com/security/data/fix/linux/rhsa-2026-38490.md) | Jul 13, 2026 |
| Linux | xorg-x11-server-Xwayland-devel almalinux 10 | 24.1.9-4.el10_2.3 | [ALSA-2026:38489](https://patchblox.com/security/data/fix/linux/alsa-2026-38489.md) | Jul 13, 2026 |
| Linux | xorg-x11-server-Xwayland-devel almalinux 9 | 24.1.9-4.el9_8.3 | [ALSA-2026:38490](https://patchblox.com/security/data/fix/linux/alsa-2026-38490.md) | Jul 13, 2026 |
| Linux | xorg-x11-server-Xwayland-devel amzn 2023 | 24.1.3-1.amzn2023.0.6 | [ALAS2023-2026-1944](https://patchblox.com/security/data/fix/linux/alas2023-2026-1944.md) | Jul 20, 2026 |
| Linux | xorg-x11-server-Xwayland-devel ol 10 | 0:24.1.9-4.el10_2.3 | [ELSA-2026-38489](https://patchblox.com/security/data/fix/linux/elsa-2026-38489.md) | Sep 1, 2026 |
| Linux | xorg-x11-server-Xwayland-devel ol 9 | 0:24.1.9-4.el9_8.3 | [ELSA-2026-38490](https://patchblox.com/security/data/fix/linux/elsa-2026-38490.md) | Sep 1, 2026 |
| Linux | xwayland Debian 14 | 2:24.1.13-1 | [DEBIAN-CVE-2026-56000](https://patchblox.com/security/data/fix/linux/debian-cve-2026-56000.md) | Jul 8, 2026 |
| Linux | xwayland opensuse-leap 16.0 | 24.1.6-160000.6.1 | [OPENSUSE-SU-2026:21283-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21283-1.md) | Jul 10, 2026 |
| Linux | xwayland sles 15.7 | 24.1.5-150700.3.22.1 | [SUSE-SU-2026:2787-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2787-1.md) | Jul 8, 2026 |
| Linux | xwayland sles 16.0 | 24.1.6-160000.6.1 | [SUSE-SU-2026:22617-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22617-1.md) | Jul 10, 2026 |

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Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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