CVE-2026-68819 — Windows Network File System Denial of Service Vulnerability

Executive Summary

Buffer over-read in Windows Network File System allows an unauthorized attacker to deny service over a network.

Overview

5.9

CVSS MEDIUM

Important

MS Severity

Not Exploited

MS Exploit Status

Exploitation Unlikely

MS Exploit Likelihood

Category Denial of Service

Released Aug 11 2026

Last Updated Aug 11 2026

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

EPSS Score 0.00645 — 0.47799 percentile

NVD CVSS 5.9 MEDIUM — matches MSRC

CVSS Vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C

ATTACK VECTOR

Network

ATTACK COMPLEXITY

High

PRIVILEGES REQUIRED

None

USER INTERACTION

None

SCOPE

Unchanged

CONFIDENTIALITY

None

INTEGRITY

None

AVAILABILITY

High

EXPLOIT CODE MATURITY

Unproven

REMEDIATION LEVEL

Official Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 5.2

EPSS Score

0.00645

probability of exploitation in the next 30 days

0.47799 percentile - updated 2026-08-14

View on FIRST.org

Affected Products

12 affected products

Product	KB Article	Severity	Impact	Restart Required
Windows 10 Version 1607 for 32-bit Systems	`5120418 (Security Update)`	Important	Denial of Service	Yes
Windows 10 Version 1607 for x64-based Systems	`5120418 (Security Update)`	Important	Denial of Service	Yes
Windows 10 Version 1809 for 32-bit Systems	`5120238 (Security Update)`	Important	Denial of Service	Yes
Windows 10 Version 1809 for x64-based Systems	`5120238 (Security Update)`	Important	Denial of Service	Yes
Windows Server 2012	`5120386 (Monthly Rollup)`	Important	Denial of Service	Yes
Windows Server 2012 (Server Core installation)	`5120386 (Monthly Rollup)`	Important	Denial of Service	Yes
Windows Server 2012 R2	`5120385 (Monthly Rollup)`	Important	Denial of Service	Yes
Windows Server 2012 R2 (Server Core installation)	`5120385 (Monthly Rollup)`	Important	Denial of Service	Yes
Windows Server 2016	`5120418 (Security Update)`	Important	Denial of Service	Yes
Windows Server 2016 (Server Core installation)	`5120418 (Security Update)`	Important	Denial of Service	Yes
Windows Server 2019	`5120238 (Security Update)`	Important	Denial of Service	Yes
Windows Server 2019 (Server Core installation)	`5120238 (Security Update)`	Important	Denial of Service	Yes

Patches

4 patches

Article	Type	Restart
`5120418`	Security Update	Yes
`5120238`	Security Update	Yes
`5120386`	Monthly Rollup	Yes
`5120385`	Monthly Rollup	Yes

Known Exploits

No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.

Acknowledgments

Lewis Lee
Seung Chan Kim

References

MSRC Advisory MITRE NVD