Use After Free in X.org X_server
CVE-2026-50263
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 disclosure.
Vulnerability class: Use-After-Free
EPSS: 0.001 (3.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
Affected products
- X.org X_server
- X.org Xwayland
- Red Hat Enterprise Linux 10 — versions 0:24.1.9-4.el10_2.2
- Red Hat Enterprise Linux 10.0 Extended Update Support — versions 0:24.1.5-6.el10_0.1
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 7 Extended Lifecycle Support — versions 0:1.20.4-35.el7_9
- Red Hat Enterprise Linux 8 — versions 0:21.1.3-20.el8_10.2, 0:1.20.11-28.el8_10.2, 0:1.15.0-10.el8_10
- Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support — versions 0:1.20.10-5.el8_4
- Red Hat Enterprise Linux 8.4 Extended Update Support Long-life Add-on — versions 0:1.20.10-5.el8_4
Weakness classification (CWE)
References
- secalert@redhat.com (x_refsource_REDHAT, Third Party Advisory, vdb-entry)
- secalert@redhat.com (x_refsource_REDHAT, issue-tracking, Third Party Advisory, Issue Tracking)
- secalert@redhat.com (Patch)
- secalert@redhat.com (Mailing List, Vendor Advisory)
- secalert@redhat.com (Permissions Required)
- secalert@redhat.com (x_refsource_REDHAT, vendor-advisory)
- secalert@redhat.com (x_refsource_REDHAT, vendor-advisory)
- secalert@redhat.com (x_refsource_REDHAT, vendor-advisory)
- secalert@redhat.com (x_refsource_REDHAT, vendor-advisory)
- secalert@redhat.com (x_refsource_REDHAT, vendor-advisory)
Frequently asked questions
- What is CVE-2026-50263?
- CVE-2026-50263 is a medium-severity vulnerability in X.org X_server, classified under Use After Free. CVSS score: 5.5/10. Published 2026-06-05.
- How severe is CVE-2026-50263?
- Medium severity. CVSS v3 base score is 5.5 out of 10.