Remote code execution via heap buffer overflow
Published Jan 13, 2026 · Updated Jan 13, 2026
Heap-based buffer overflow in Microsoft Windows RRAS allows remote attackers to execute code over a network after user interaction. Microsoft has not disclosed the affected RRAS function, input format, or the operation that overruns the heap allocation. Exploitation requires no privileges but does require user interaction; successful exploitation runs attacker-controlled code in the affected process.
Summary
What happened
Heap-based buffer overflow in Microsoft Windows RRAS allows remote attackers to execute code over a network after user interaction. Microsoft has not disclosed the affected RRAS function, input format, or the operation that overruns the heap allocation. Exploitation requires no privileges but does require user interaction; successful exploitation runs attacker-controlled code in the affected process.
The record
- CVE
- CVE-2026-20868
- Published
- Jan 13, 2026
- Updated
- Jan 13, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2019
- Classifications
- CWE-122, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 13, 2026CVE publishedPublication date reported by the CVE source.
- Jan 13, 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=10.0.17763.0 <10.0.17763.8276
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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.
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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