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NVD / CVE Program· CNA microsoft

CVE-2026-62877: Windows Win32k Elevation of Privilege Vulnerability

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.33% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Microsoft Office 365 for Mac 16.112.26090911; Microsoft Office for Android 16.0.20430.20000; Microsoft Office LTSC for Mac 2021 16.112.26090911.

Low priority for now. Upgrade to Microsoft Office 365 for Mac 16.112.26090911; Microsoft Office for Android 16.0.20430.20000; Microsoft Office LTSC for Mac 2021 16.112.26090911 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Stack-based buffer overflow in Windows Win32K allows an authorized attacker to elevate privileges locally.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Aug 11, 2026
Updated
Oct 30, 2026
EPSS
0.3% · 26th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · microsoft
7.8
NVD has not scored this yet; the score shown is the CNA’s.

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-62877

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
microsoftwindows 10 1607
microsoftwindows 10 1809
microsoftwindows 10 21h2
microsoftwindows 10 22h2
microsoftwindows 11 23h2
microsoftwindows 11 24h2
microsoftwindows 11 25h2
microsoftwindows 11 26h1
microsoftwindows server 2012
microsoftwindows server 2016
microsoftwindows server 2019
microsoftwindows server 2022

and 1 more

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • microsoft windows 10 1607before 10.0.14393.9418
  • microsoft windows 10 1809before 10.0.17763.9115
  • microsoft windows 10 21h2before 10.0.19044.7663
  • microsoft windows 10 22h2before 10.0.19045.7663
  • microsoft windows 11 23h2before 10.0.22631.7517
  • microsoft windows 11 24h2before 10.0.26100.9106
  • microsoft windows 11 25h2before 10.0.26200.9106
  • microsoft windows 11 26h1before 10.0.28000.2704
  • microsoft windows server 2012all versions
  • microsoft windows server 2012r2
  • microsoft windows server 2016before 10.0.14393.9418
  • microsoft windows server 2019before 10.0.17763.9115
  • microsoft windows server 2022before 10.0.20348.5440
  • microsoft windows server 2025before 10.0.26100.33222

Versions reported by the vendor

Affected version ranges reported by the assigning authority (microsoft). Independent of NVD's CPE analysis and usually ahead of it.

  • Microsoft Microsoft Office 365 for Mac

    • 1.0.0 and later · before 16.112.26090911affected

  • Microsoft Microsoft Office for Android

    • 16.0.1 and later · before 16.0.20430.20000affected

  • Microsoft Microsoft Office LTSC for Mac 2021

    • 16.0.1 and later · before 16.112.26090911affected

  • Microsoft Microsoft Office LTSC for Mac 2024

    • 16.0.0 and later · before 16.112.26090911affected

Same product

microsoft: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-33824Windows Internet Key Exchange (IKE) Service Extensions Remote Code Execution VulnerabilityKEV
    92Now
  • CVE-2018-8174A remote code execution vulnerability exists in the way that the VBScript engine handles objects in memory, aka "Windows VBScript Engine RemKEV
    86Now
  • CVE-2026-21510Windows Shell Security Feature Bypass VulnerabilityKEV
    83Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-62795Aug 11, 2026 · Windows LDAP - Lightweight Directory Access Protocol Remote Code Execution Vulnerability
    35Monitor
  • ← EarlierCVE-2026-62824Aug 11, 2026 · Remote Desktop Client Remote Code Execution Vulnerability
    35Monitor
  • Later →CVE-2026-68820Aug 11, 2026 · Windows Ancillary Function Driver for WinSock Elevation of Privilege VulnerabilityKEV
    61This week

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Microsoft Office 365 for Mac16.112.26090911 · Release NotesMicrosoft (MSRC)
Microsoft Office for Android16.0.20430.20000 · Release NotesMicrosoft (MSRC)
Microsoft Office LTSC for Mac 202116.112.26090911 · Release NotesMicrosoft (MSRC)
Microsoft Office LTSC for Mac 202416.112.26090911 · Release NotesMicrosoft (MSRC)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-628780 days apartWindows DNS Server Remote Code Execution Vulnerability
    39Monitor
  • CVE-2026-6991028 days apartWindows Hyper-V Remote Code Execution Vulnerability
    39Monitor
  • CVE-2026-7298228 days apartWindows Netlogon Remote Code Execution Vulnerability
    39Monitor
  • CVE-2026-4481563 days apartDHCP Client Service Remote Code Execution Vulnerability
    39Monitor
  • CVE-2026-8580663 days apartNetwork Policy Server (NPS) Remote Code Execution Vulnerability
    39Monitor
  • CVE-2026-628240 days apartRemote Desktop Client Remote Code Execution Vulnerability
    35Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-121 · Stack-based Buffer Overflow

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records