What is the CVSS score of CVE-2026-50498?

CVE-2026-50498 has a CVSS 3.1 base score of 7.8 (High). CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.3%.

Which versions of Microsoft Windows are affected by CVE-2026-50498?

Windows Universal Disk Format (UDF) driver vulnerability allows local users to escalate privileges by opening malicious ISO files.. A patch is available.

How to fix or mitigate CVE-2026-50498?

Within 24 hours, identify all Windows endpoints and servers through WSUS, Intune, or System Center asset inventory to establish patch baseline and identify high-risk systems. Within 7 days, deploy the available Microsoft patch for CVE-2026-50498 UDFS driver via Windows Update, WSUS, or manual patching, prioritizing systems where users regularly mount ISO files or interact with external media. Within 30 days, verify patch deployment to 95%+ of the Windows fleet via WSUS compliance reports and implement application-level controls (AppLocker, Windows Defender Application Control) restricting ISO and UDF file operations to authorized sources.

Microsoft Windows CVE-2026-50498

EUVD-2026-44105 HIGH

Out-of-bounds Read (CWE-125)

2026-07-14 microsoft

GHSA-77fr-5p3g-f5p5

Buffer Overflow Information Disclosure Microsoft Windows Server 2012 Windows Server 2016 Windows Server 2019 Windows Server 2022 Windows Server 2025 Windows 10 Version 1607 Windows 10 Version 1809 Windows 10 Version 21H2 Windows 10 Version 22H2 Windows Server 2016 Server Core Installation Windows Server 2019 Server Core Installation Windows 11 Version 24H2 Windows 11 Version 25H2 Windows 11 Version 26H1 Windows Server 2025 Server Core Installation Windows Server 2012 Server Core Installation Windows Server 2012 R2 Windows Server 2012 R2 Server Core Installation

7.8

CVSS 3.1 · NVD

Severity by source

Vendor (microsoft) PRIMARY

HIGH

qualitative

NVD

7.8 HIGH

AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

vuln.today AI

7.8 HIGH

Local kernel-driver flaw needing a user to mount crafted UDF media (AV:L/UI:R) with no prior privileges (PR:N), yielding kernel-level escalation with high C/I/A.

3.1 AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

4.0 AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (microsoft).

CVSS VectorNVD

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Jul 14, 2026 - 19:59 vuln.today

CVE Published

Jul 14, 2026 - 17:07 nvd

HIGH 7.8

DescriptionNVD

Windows Universal Disk Format File System Driver (UDFS) Elevation of Privilege Vulnerability

AnalysisAI

Elevation of privilege in the Microsoft Windows Universal Disk Format File System driver (UDFS) allows a local attacker to gain higher privileges after a user mounts or opens a maliciously crafted UDF-formatted volume such as an ISO or disc image. The flaw is an out-of-bounds read (CWE-125) in the kernel-mode UDFS parser, and successful exploitation yields high impact to confidentiality, integrity, and availability (CVSS 7.8). No public exploit identified at time of analysis and it is not listed in CISA KEV, but Microsoft has released a patch.

Technical ContextAI

The vulnerability lives in the Windows kernel-mode driver (udfs.sys) that implements the Universal Disk Format (UDF/ISO 13346) filesystem used for optical media, disc images, and ISO files that Windows can natively mount by double-click. The CWE-125 out-of-bounds read indicates the driver reads memory beyond an allocated buffer while parsing attacker-controlled on-disk UDF structures such as volume descriptors, file entries, or extent metadata; the accompanying 'Buffer Overflow' and 'Information Disclosure' tags suggest malformed length or offset fields drive the parser past its buffer bounds. Because UDFS runs in kernel context, a parsing error that corrupts or leaks kernel memory can be leveraged to escalate from a normal user toward elevated/SYSTEM privileges. The CPE set confirms the flaw spans the shared Windows codebase from Windows 10 1607 and Server 2012 through Windows 11 26H1 and Server 2025.

RemediationAI

Apply the Microsoft security update for CVE-2026-50498 for your specific Windows or Windows Server build; Patch available per vendor advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50498, which lists the exact fixed build per OS version, so confirm the KB/build for each affected image rather than expecting a single cross-platform version. Because exploitation depends on a user mounting attacker-supplied UDF media, compensating controls until patching include blocking or quarantining inbound ISO/IMG/UDF disc-image files at the email gateway and web proxy (trade-off: may impede legitimate software distribution), and using Group Policy, AppLocker, or attack-surface-reduction rules to prevent auto-mounting of untrusted disc images (trade-off: disrupts workflows that rely on mounting ISOs). Restricting delivery of removable and virtual media to untrusted users reduces the user-interaction opportunity this vulnerability requires.