Windows Push Notifications: Use-after-free allows local privilege escalation
Summary
A use-after-free flaw (CWE-416) in the Windows Push Notifications service allows an authorized local user to elevate privileges. The attack is not possible remotely and requires high complexity and low privileges. Affected are Windows 10, Windows 11 and Windows Server 2019 to 2025 systems, with Windows 10 1809 and Server 2019 among them.
Affected
- Windows 10 Version 1809 (10.0.17763.0 to < 10.0.17763.9376)
- Windows Server 2019 and Server Core installation (10.0.17763.0 to < 10.0.17763.9376)
- Windows 10 Version 21H2 (10.0.19044.0 to < 10.0.19044.7807) and 22H2 (10.0.19045.0 to < 10.0.19045.7807)
- Windows 11 Version 23H2 (10.0.22631.0 to < 10.0.22631.7652) and 24H2 (10.0.26100.0 to < 10.0.26100.9711)
- Windows 11 Version 25H2 (10.0.26200.0 to < 10.0.26200.9711) and 26H2 (10.0.26300.0 to < 10.0.26300.9711)
- Windows 11 Version 26H1 (10.0.28000.0 to < 10.0.28000.3231)
- Windows Server 2022 (10.0.20348.0 to < 10.0.20348.5761)
- Windows Server 2025 and Server Core installation (10.0.26100.0 to < 10.0.26100.33650)
Fixed in
- Windows 10 1809 and Server 2019: build 10.0.17763.9376
- Windows 10 21H2: build 10.0.19044.7807
- Windows 10 22H2: build 10.0.19045.7807
- Windows 11 23H2: build 10.0.22631.7652
- Windows 11 24H2: build 10.0.26100.9711
- Windows 11 25H2: build 10.0.26200.9711
- Windows 11 26H1: build 10.0.28000.3231
- Windows 11 26H2: build 10.0.26300.9711
- Windows Server 2022: build 10.0.20348.5761
- Windows Server 2025: build 10.0.26100.33650
Verify the exact builds and KB numbers on the MSRC advisory before rollout.
Workaround
Unknown. No vendor-documented workaround was found; the security update is the only confirmed remedy.
Exploitation
- No evidence of exploitation in the wild.
- CISA SSVC: exploitation none, automatable no, technical impact total.
- No public proof of concept found for this CVE. A PoC exists for a different CVE in the same component (CVE-2026-42978).
- EPSS about 0.27%.
Our recommendation
- Install the October 2026 cumulative update for your Windows version (Windows Update, WSUS or Microsoft Update Catalog).
- Prioritise multi-user systems, terminal and RDS servers, and any remaining Windows 10 1809 systems, which should also be scheduled for upgrade.
- Restrict local logon to trusted users and monitor for unexpected privilege changes.
- Check the MSRC advisory directly, since NVD and aggregator data differ in status and CVSS scores.
Information from Microsoft (Patch Tuesday October 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Windows Push Notifications
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5126651, KB5126655, KB5126657, KB5126646, KB5127648, KB5126653
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-70198 msrc.microsoft.com
- Vulners CVE list entry (CNA record) vulners.com
- Vulners Microsoft MSCVE entry vulners.com
- VulDB entry CVE-2026-70198 vuldb.com
- OpenCVE CVE-2026-70198 app.opencve.io
- Strix CVE-2026-70198 www.strix.ai
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 4 Nov 2026, 09:04.
Original description (NVD)
Use after free in Windows Push Notifications allows an authorized attacker to elevate privileges locally.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
Affected? We can help.
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