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TI-2026-72598 Aliases CVE-2026-83856GHSA-fw5f-5j4p-c43m

Out-of-bounds read in Windows Event Logging Service

Priority LOW 38CWE-125Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA.

Summary

Microsoft Windows 11 and Windows Server 2022 and 2025 are affected. An out-of-bounds read (CWE-125) in the Windows Event Logging Service lets a remote attacker read memory outside the intended buffer. An unauthorized attacker can execute code over a network, although the attack is hard to carry out and needs no privileges or user interaction.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

Out-of-bounds read in Windows Event Logging Service allows an unauthorized attacker to execute code over a network.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00631 50th percentileScored 2026-11-07
Fix Fixed Windows 11 version 23H2 (Microsoft): 10.0.22631.7652Windows 11 Version 23H2 (Microsoft): 10.0.22631.7652+7 more products

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MicrosoftWindows 11 version 23H210.0.22631.0 to before 10.0.22631.765210.0.22631.7652Patch availableCNA
MicrosoftWindows 11 Version 23H210.0.22631.0 to before 10.0.22631.765210.0.22631.7652Patch availableCNA
MicrosoftWindows 11 Version 24H210.0.26100.0 to before 10.0.26100.971110.0.26100.9711Patch availableCNA
MicrosoftWindows 11 Version 25H210.0.26200.0 to before 10.0.26200.971110.0.26200.9711Patch availableCNA
MicrosoftWindows 11 version 26H110.0.28000.0 to before 10.0.28000.323110.0.28000.3231Patch availableCNA
MicrosoftWindows 11 Version 26H210.0.26300.0 to before 10.0.26300.971110.0.26300.9711Patch availableCNA
MicrosoftWindows Server 202210.0.20348.0 to before 10.0.20348.576110.0.20348.5761Patch availableCNA
MicrosoftWindows Server 202510.0.26100.0 to before 10.0.26100.3365010.0.26100.33650Patch availableCNA
MicrosoftWindows Server 2025 (Server Core installation)10.0.26100.0 to before 10.0.26100.3365010.0.26100.33650Patch availableCNA
  • Windows 11 version 23H2 VendorMicrosoft Affected 10.0.22631.0 to before 10.0.22631.7652 Fixed in 10.0.22631.7652 Patch available CNA
  • Windows 11 Version 23H2 VendorMicrosoft Affected 10.0.22631.0 to before 10.0.22631.7652 Fixed in 10.0.22631.7652 Patch available CNA
  • Windows 11 Version 24H2 VendorMicrosoft Affected 10.0.26100.0 to before 10.0.26100.9711 Fixed in 10.0.26100.9711 Patch available CNA
  • Windows 11 Version 25H2 VendorMicrosoft Affected 10.0.26200.0 to before 10.0.26200.9711 Fixed in 10.0.26200.9711 Patch available CNA
  • Windows 11 version 26H1 VendorMicrosoft Affected 10.0.28000.0 to before 10.0.28000.3231 Fixed in 10.0.28000.3231 Patch available CNA
  • Windows 11 Version 26H2 VendorMicrosoft Affected 10.0.26300.0 to before 10.0.26300.9711 Fixed in 10.0.26300.9711 Patch available CNA
  • Windows Server 2022 VendorMicrosoft Affected 10.0.20348.0 to before 10.0.20348.5761 Fixed in 10.0.20348.5761 Patch available CNA
  • Windows Server 2025 VendorMicrosoft Affected 10.0.26100.0 to before 10.0.26100.33650 Fixed in 10.0.26100.33650 Patch available CNA
  • Windows Server 2025 (Server Core installation) VendorMicrosoft Affected 10.0.26100.0 to before 10.0.26100.33650 Fixed in 10.0.26100.33650 Patch available CNA

CPE configurations NVD · 12

CPEVersionsRoleVendor
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:*before 10.0.22631.7652VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:*before 10.0.22631.7652VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:*before 10.0.26100.9711VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:*before 10.0.26100.9711VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:*before 10.0.26200.9711VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:*before 10.0.26200.9711VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:arm64:*before 10.0.28000.3231VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:x64:*before 10.0.28000.3231VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_11_26h2:*:*:*:*:*:*:arm64:*before 10.0.26300.9711VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_11_26h2:*:*:*:*:*:*:x64:*before 10.0.26300.9711VulnerableMicrosoft
  • cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:* Versions before 10.0.22631.7652 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:* Versions before 10.0.22631.7652 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:* Versions before 10.0.26100.9711 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:* Versions before 10.0.26100.9711 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:* Versions before 10.0.26200.9711 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:* Versions before 10.0.26200.9711 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:arm64:* Versions before 10.0.28000.3231 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:x64:* Versions before 10.0.28000.3231 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_11_26h2:*:*:*:*:*:*:arm64:* Versions before 10.0.26300.9711 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_11_26h2:*:*:*:*:*:*:x64:* Versions before 10.0.26300.9711 Vulnerable ·Microsoft
Show 2 more CPE
CPEVersionsRoleVendor
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*before 10.0.20348.5761VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:*before 10.0.26100.33650VulnerableMicrosoft
  • cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:* Versions before 10.0.20348.5761 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:* Versions before 10.0.26100.33650 Vulnerable ·Microsoft

Remediation

Fixed versions are Windows 11 version 23H2 10.0.22631.7652, Windows 11 version 24H2 10.0.26100.9711, Windows 11 version 25H2 10.0.26200.9711, Windows 11 version 26H1 10.0.28000.3231, Windows 11 version 26H2 10.0.26300.9711, Windows Server 2022 10.0.20348.5761, and Windows Server 2025 including Server Core installations 10.0.26100.33650.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

  • Fix · CNA Windows 11 version 23H2 (Microsoft) Fixed in 10.0.22631.7652
  • Fix · CNA Windows 11 Version 23H2 (Microsoft) Fixed in 10.0.22631.7652
  • Fix · CNA Windows 11 Version 24H2 (Microsoft) Fixed in 10.0.26100.9711
  • Fix · CNA Windows 11 Version 25H2 (Microsoft) Fixed in 10.0.26200.9711
  • Fix · CNA Windows 11 version 26H1 (Microsoft) Fixed in 10.0.28000.3231
  • Fix · CNA Windows 11 Version 26H2 (Microsoft) Fixed in 10.0.26300.9711
  • Fix · CNA Windows Server 2022 (Microsoft) Fixed in 10.0.20348.5761
  • Fix · CNA Windows Server 2025 (Microsoft) Fixed in 10.0.26100.33650
  • Fix · CNA Windows Server 2025 (Server Core installation) (Microsoft) Fixed in 10.0.26100.33650

Timeline

  1. 2026-10-13 Threatist record created from CVE-2026-83856
  2. 2026-10-13 Alias added: GHSA-fw5f-5j4p-c43m
  3. 2026-10-21 CVSS score added · NVD
  4. 2026-10-27 EPSS moved to the 50th–90th percentile

References

Patch 1

  • TI-2026-26194 Windows Internet Key Exchange (IKE) Service Extensions Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-73128 Windows Shell Security Feature Bypass Vulnerability KEVCVSS 3.1HIGH 8.8
  • TI-2026-17367 MSHTML Framework Security Feature Bypass Vulnerability KEVCVSS 3.1HIGH 8.8
  • TI-2026-17364 Windows Shell Security Feature Bypass Vulnerability KEVCVSS 3.1HIGH 8.8
  • TI-2025-24062 Windows SMB Client Elevation of Privilege Vulnerability KEVCVSS 3.1HIGH 8.8
  • TI-2025-24042 Internet Shortcut Files Remote Code Execution Vulnerability KEVCVSS 3.1HIGH 8.8
See all 3407 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences