CVE-2026-56000
published 2026-07-08CVE-2026-56000: 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…
PriorityP342high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
EPSS
0.22%
12.9th percentile
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.
Affected
4 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| the_x.org_foundation | xorg-x11-server | — | — |
| x.org | x_server | < 21.2.24 | 21.2.24 |
| x.org | xorg-x11-server | < 21.1.24 | 21.1.24 |
| x.org | xwayland | < 24.1.13 | 24.1.13 |
CVSS provenance
nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvdv4.09.0CRITICALCVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
vendor_redhat9.0CRITICAL
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GHSA
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() poin
ghsa_unreviewed·2026-07-08
CVE-2026-56000 [CRITICAL] CWE-416 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() poin
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.
Red Hat
X.org: xorg-x11-server: GLX contextTags Use-After-Free in CommonMakeCurrent()
vendor_redhat·2026-07-08·CVSS 9.0
CVE-2026-56000 [CRITICAL] CWE-825 X.org: xorg-x11-server: GLX contextTags Use-After-Free in CommonMakeCurrent()
X.org: xorg-x11-server: GLX contextTags Use-After-Free in CommonMakeCurrent()
A flaw was found in the X.org X11 server, specifically within the GLX (OpenGL Extension to the X Window System) dispatch layer. A remote attacker can exploit this vulnerability by sending a series of crafted X11 requests. This can lead to a use-after-free condition, where the server attempts to write data to memory that has already been released. The primary consequence of this memory corruption is a denial of service, potentially causing the X server to crash.
Statement: An Important use-after-free vulnerability in the X.org X11 server's GLX dispatch layer allows a remote, unauthenticated attacker to trigger a denial of service. By sending a sequence of crafted X11 requests, an attacker can cause the X server
No detection rules found.
No public exploits indexed.
2026-07-08
Published