X.org X11 Server CreateSaverWindow use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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4.4$0-$5k8.19

Summaryinfo

A vulnerability was found in X.org X11 Server. It has been classified as critical. Affected by this issue is the function CreateSaverWindow. Performing a manipulation results in use after free. This vulnerability is cataloged as CVE-2026-50263. The attack must be initiated from a local position. There is no exploit available.

Detailsinfo

A vulnerability classified as problematic has been found in X.org X11 Server (unknown version). This affects the function CreateSaverWindow. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality. The summary by CVE is:

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.

It is possible to read the advisory at access.redhat.com. This vulnerability is uniquely identified as CVE-2026-50263 since 06/04/2026. The exploitability is told to be easy. Attacking locally is a requirement. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 318747 (Linux Distros Unpatched Vulnerability : CVE-2026-50263), which helps to determine the existence of the flaw in a target environment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at Tenable (318747). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

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Vendor

Name

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.4
VulDB Meta Temp Score: 4.4

VulDB Base Score: 3.3
VulDB Temp Score: 3.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 5.5
CNA Vector (redhat): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 318747
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-50263

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

06/04/2026 CVE reserved
06/05/2026 +1 days Advisory disclosed
06/05/2026 +0 days VulDB entry created
06/05/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: x.org

Advisory: access.redhat.com
Status: Not defined

CVE: CVE-2026-50263 (🔒)
GCVE (CVE): GCVE-0-2026-50263
GCVE (VulDB): GCVE-100-368919

Entryinfo

Created: 06/05/2026 14:06
Updated: 06/05/2026 17:52
Changes: 06/05/2026 14:06 (62), 06/05/2026 17:52 (2)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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