CVE-2026-103558: Windows Routing and Remote Access Service (RRAS) Denial of Service Vulnerability
Deadlock in Windows Routing and Remote Access Service (RRAS) allows an unauthorized attacker to deny service over a network.
Other sources
Windows Routing and Remote Access Service (RRAS) Denial of Service Vulnerability
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.3.9600.23470Patch KB5126836 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26100.9711Patch KB5127648 - Upgrade
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Fixed in 10.0.20348.5761Patch KB5126655 - Upgrade
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Fixed in 10.0.19044.7807Patch KB5126657 - Upgrade
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Fixed in 10.0.22631.7652Patch KB5126653 - Upgrade
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Fixed in 10.0.17763.9376Patch KB5126651 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.14393.9612Patch KB5126868 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26200.9711Patch KB5127648 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.28000.3231Patch KB5127646 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.2.9200.26434Patch KB5126835 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26300.9711Patch KB5127648 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26100.33650Patch KB5126646
Event History
Frequently Asked Questions
What access does an attacker need to exploit this issue?
The vulnerability is exploitable remotely over a network and does not require authentication, user interaction, or prior privileges.
What is the expected impact if exploitation succeeds?
Exploitation can cause a denial of service by triggering a deadlock in the Windows Routing and Remote Access Service. The provided impact data indicates availability impact only, with no stated confidentiality or integrity impact.
Which systems should be prioritized for assessment?
Assess Microsoft Windows 10, Windows 11, and Windows Server 2012, 2012 R2, 2016, 2019, 2022, and 2025 systems, particularly where the Routing and Remote Access Service is exposed to untrusted networks.