Type Vulnerability
An integer underflow vulnerability in Windows Installer could allow an authorised attacker to elevate privileges locally.
Integer underflow (wrap or wraparound) in Windows Installer allows an authorized attacker to elevate privileges locally
CVE-2026-83676
What this means
This is rated high severity (7 out of 10). There is no confirmed exploitation of it yet. Ask IT whether Microsoft Windows 10 21h2, Microsoft Windows 10 22h2 and Microsoft Windows 11 23h2, and 6 more are in your estate, and treat that as the priority.
Full vendor description
Integer underflow (wrap or wraparound) in Windows Installer allows an authorized attacker to elevate privileges locally.
Scoring and exploitation
7.0/ 10
CVSS 3.1 base scoreHigh
Exploitable only with local access and a low-privilege account, under specific conditions, and no one has to click or open anything. High impact on confidentiality, integrity and availability.
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Exploitability
Longer bar: easier to attack
Attack vectorLocalAV:L
Attack complexityHighAC:H
Privileges requiredLowPR:L
User interactionNoneUI:N
ScopeUnchangedS:U
Impact
Longer bar: more harm
ConfidentialityHighC:H
IntegrityHighI:H
AvailabilityHighA:H
- ~0.3% estimated chance of attack in 30 daysModel estimate (): a probability signal, not confirmed exploitation
- Exploited in the wild
- Not confirmed in the
- Not reported
Weaknesses
CWE-122CWE-191
Affected products ()
- Microsoft Windows 10 21h2
- Microsoft Windows 10 22h2
- Microsoft Windows 11 23h2
- Microsoft Windows 11 24h2
- Microsoft Windows 11 25h2
- Microsoft Windows 11 26h1
- Microsoft Windows 11 26h2
- Microsoft Windows Server 2022
- Microsoft Windows Server 2025
Show the raw CPE strings (18)
- cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:arm64:*
- cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x64:*
- cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x86:*
- cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:arm64:*
- cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x64:*
- cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x86:*
- cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:*
- cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:*
- cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:*
- cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:*
- cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:*
- cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:*
- cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:arm64:*
- cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:x64:*
- cpe:2.3:o:microsoft:windows_11_26h2:*:*:*:*:*:*:arm64:*
- cpe:2.3:o:microsoft:windows_11_26h2:*:*:*:*:*:*:x64:*
- cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:x64:*
- cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:*
References
1 link from the CVE record, grouped by site; the vendor's advisory comes first.
msrc.microsoft.com1 linkVendor advisory
- CVE-2026-83676 (opens in a new tab)Patch · Vendor Advisory