CVE-2026-61920

MEDIUM 6.6 ALL-YEARS

Published 2026-08-11 · Last modified 2026-10-21 · microsoft · NVD: Analyzed

Concurrent execution using shared resource with improper synchronization ('race condition') in Windows DNS allows an authorized attacker to execute code over a network.

LIMITED SIGNALS

No known exploitation, public exploit, or elevated probability at this time. Track for changes.

Exploitation likelihood

0.5%chance of exploitation in 30 days · 44th percentile

○ In CISA KEV○ Catalogued PoC◆ SSVC: exploitation none, automatable no

Impact if exploited

6.6CVSS 3.1 · MEDIUM · CNA

ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

What an attacker needs

✓Access: Reachable over the network — no local access needed
⚠Privileges: Requires an admin / high-privilege account
✓User interaction: No user interaction needed
⚠Complexity: Needs a race window or specific setup

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept

No public PoC is currently catalogued.

Search for new PoCs

Search GitHub now — results may be empty or unverified.

Tracked sources are checked weekly for the full archive, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.

Affected

Vendors Microsoft

Products Windows Server 2012 R2 Windows Server 2012 R2 (Server Core Installation) Windows Server 2016 Windows Server 2016 (Server Core Installation) Windows Server 2019 Windows Server 2019 (Server Core Installation) Windows Server 2022 Windows Server 2025 Windows Server 2025 (Server Core Installation) Windows 10 1607 Windows 10 1809 Windows 11 26h1 Windows Server 2012

Weakness (CWE)

CWE-362: : Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CWE-416: : Use After Free

CVSS vector

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

References and research data (JSON)

Known Affected Software Configurations

Vendor	Product	Version range
Microsoft	Windows 10 1607	< 10.0.14393.9418
Microsoft	Windows 10 1607	< 10.0.14393.9418
Microsoft	Windows 10 1809	< 10.0.17763.9121
Microsoft	Windows 10 1809	< 10.0.17763.9121
Microsoft	Windows 11 26h1	< 10.0.28000.2704
Microsoft	Windows 11 26h1	< 10.0.28000.2704
Microsoft	Windows Server 2012	r2
Microsoft	Windows Server 2016	< 10.0.14393.9418
Microsoft	Windows Server 2019	< 10.0.17763.9121
Microsoft	Windows Server 2022	< 10.0.20348.5440
Microsoft	Windows Server 2025	< 10.0.26100.33222

All CVSS metrics

MEDIUM 6.6 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
MEDIUM 6.6 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

References

Patches & mitigations

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-61920 vendor-advisorypatchPatchVendor AdvisoryCVE record · microsoft · Updated 2026-10-21T20:53:28.061Z
NVD · CVE-2026-61920 · Updated 2026-09-02T18:20:38.667

Advisories

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-56622 ADVISORYEUVD · EUVD-2026-56622

Sources: NVD · CVE.org · All sources and attribution · EPSS