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PatchSiren cyber security CVE debrief

CVE-2026-50263 Red Hat CVE debrief

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. This vulnerability has a CVSS score of 5.5 and a severity of MEDIUM.

Vendor
Red Hat
Product
Red Hat Enterprise Linux 10
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-05
Original CVE updated
2026-07-27
Advisory published
2026-06-05
Advisory updated
2026-07-27

Who should care

Users of X.Org X server and Xwayland should be aware of this vulnerability. Specifically, users of Red Hat Enterprise Linux 7, 8, 9, and 10 may be affected.

Technical summary

The vulnerability is caused by a use-after-free flaw in the CreateSaverWindow() function. This flaw allows a client to trigger a use-after-free read, potentially leading to information disclosure.

Defensive priority

MEDIUM

Recommended defensive actions

  • Apply the patches provided by the vendor.
  • Restrict access to the X server and Xwayland.
  • Monitor for suspicious activity.

Evidence notes

The CVE record and NVD detail pages provide additional information about this vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-50263 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-50263

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-50263 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-50263

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.