Unauthenticated network-triggered service interruption
Published Mar 11, 2021 · Updated Aug 19, 2026
Denial of service in Windows Network Address Translation allows remote attackers to interrupt affected Windows systems over a network. Microsoft has not published the vulnerable NAT code path or the malformed network input that triggers the failure. No authentication or user interaction is required, and the documented consequence is limited to availability loss.
Summary
What happened
Denial of service in Windows Network Address Translation allows remote attackers to interrupt affected Windows systems over a network. Microsoft has not published the vulnerable NAT code path or the malformed network input that triggers the failure. No authentication or user interaction is required, and the documented consequence is limited to availability loss.
The record
- CVE
- CVE-2021-26879
- Published
- Mar 11, 2021
- Updated
- Aug 19, 2026
- Vendor
- Microsoft
- Product
- Windows 10 Version 1507
- Classifications
- T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 11, 2021CVE publishedPublication date reported by the CVE source.
- Aug 19, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.10240.0 <10.0.10240.18874
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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