CVE-2026-85837: Out-of-bounds read in Windows Kernel allows an authorized attacker to elevate privileges locally.

Q: How do I fix CVE-2026-85837?

windows 11 24h2: upgrade to 10.0.26100.9711; windows 11 25h2: upgrade to 10.0.26200.9711; windows 11 26h1: upgrade to 10.0.28000.3231. Exact commands for each OS are on this page.

Q: Is CVE-2026-85837 being exploited?

CVE-2026-85837 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-85837 affect?

CVE-2026-85837 affects windows 11 24h2, windows 11 25h2, windows 11 26h1. Severity is high (CVSS 7.8). Out-of-bounds read in Windows Kernel allows an authorized attacker to elevate privileges locally.

Q: How urgent is CVE-2026-85837?

Priority 38/100. High severity; On your watchlist

Routine

HIGH 7.8WATCHLISTUPGRADEUPGRADEUPGRADE

CVE-2026-85837 is a high-severity flaw (CVSS 7.8) affecting windows 11 24h2, windows 11 25h2, windows 11 26h1. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Out-of-bounds read in Windows Kernel allows an authorized attacker to elevate privileges locally.

Why this priority

High severity
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.8 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.3% (top 76%)
CISA exploited list	No
Weakness	CWE-125
Published	2026-10-13
Last modified	2026-10-16

Publisher (CNA): Microsoft Corporation · Vendor: microsoft

Last updated 2026-10-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-10-13 19:21 UTCPublished CVE record published
2026-10-16 17:31 UTCUpdated Record last modified

microsoft windows 11 24h2 UPGRADE

Affected: < 10.0.26100.9711

Fixed in: 10.0.26100.9711

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

microsoft windows 11 25h2 UPGRADE

Affected: < 10.0.26200.9711

Fixed in: 10.0.26200.9711

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

microsoft windows 11 26h1 UPGRADE

Affected: < 10.0.28000.3231

Fixed in: 10.0.28000.3231

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

microsoft windows 11 26h2 UPGRADE

Affected: < 10.0.26300.9711

Fixed in: 10.0.26300.9711

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

microsoft windows server 2025 UPGRADE

Affected: < 10.0.26100.33650

Fixed in: 10.0.26100.33650

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-85837?

windows 11 24h2: upgrade to 10.0.26100.9711; windows 11 25h2: upgrade to 10.0.26200.9711; windows 11 26h1: upgrade to 10.0.28000.3231. Exact commands for each OS are on this page.

Is CVE-2026-85837 being exploited?

CVE-2026-85837 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-85837 affect?

CVE-2026-85837 affects windows 11 24h2, windows 11 25h2, windows 11 26h1. Severity is high (CVSS 7.8). Out-of-bounds read in Windows Kernel allows an authorized attacker to elevate privileges locally.

How urgent is CVE-2026-85837?

Priority 38/100. High severity; On your watchlist

Software pages

Windows vulnerabilities · Windows Server vulnerabilities

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References

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