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CVE-2026-65789

HIGH 8.1 ALL-YEARS

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

Use after free in Windows DNS allows an unauthorized attacker to execute code over a network.

ELEVATED IMPACT

Severe if exploited (CVSS 8.1), but no confirmed exploitation. Patch on a normal cadence.

Exploitation likelihood

0.7%chance of exploitation in 30 days · 53rd percentile

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

Impact if exploited

8.1CVSS 3.1 · HIGH · CNA

ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

What an attacker needs

✓Access: Reachable over the network — no local access needed
✓Privileges: No account or privileges required
✓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

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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 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

Weakness (CWE)

CWE-416: : Use After Free

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/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 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

HIGH 8.1 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
HIGH 8.1 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Patches & mitigations

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-65789 vendor-advisorypatchPatchVendor AdvisoryCVE record · microsoft · Updated 2026-10-21T20:52:33.592Z
NVD · CVE-2026-65789 · Updated 2026-09-02T18:21:06.070

Advisories

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-56442 ADVISORYEUVD · EUVD-2026-56442

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