CVE-2025-21276: CWE-191: Integer Underflow (Wrap or Wraparound) in Microsoft Windows 10 Version 1507
Windows MapUrlToZone Denial of Service Vulnerability
AI Analysis
Technical Summary
This vulnerability (CVE-2025-21276) involves an integer underflow (CWE-191) in the MapUrlToZone function of Microsoft Windows 10 Version 1507 (build 10.0.10240.0). The flaw can be exploited remotely without privileges or user interaction to cause a denial of service (DoS) by crashing the affected system. The vulnerability has a CVSS v3.1 base score of 7.5, indicating high severity. Microsoft has released an official fix for this issue as documented in their security update guide.
Potential Impact
Successful exploitation results in denial of service, causing system instability or crash. There is no impact on confidentiality or integrity. The vulnerability can be triggered remotely without authentication or user interaction.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the security update provided in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21276 to remediate this vulnerability.
CVE-2025-21276: CWE-191: Integer Underflow (Wrap or Wraparound) in Microsoft Windows 10 Version 1507
Description
Windows MapUrlToZone Denial of Service Vulnerability
CVSS v3.1
Score 7.5high
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2025-21276) involves an integer underflow (CWE-191) in the MapUrlToZone function of Microsoft Windows 10 Version 1507 (build 10.0.10240.0). The flaw can be exploited remotely without privileges or user interaction to cause a denial of service (DoS) by crashing the affected system. The vulnerability has a CVSS v3.1 base score of 7.5, indicating high severity. Microsoft has released an official fix for this issue as documented in their security update guide.
Potential Impact
Successful exploitation results in denial of service, causing system instability or crash. There is no impact on confidentiality or integrity. The vulnerability can be triggered remotely without authentication or user interaction.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the security update provided in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21276 to remediate this vulnerability.
Technical Details
- Data Version
- 5.1
- Assigner Short Name
- microsoft
- Date Reserved
- 2024-12-10T23:54:12.937Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21276","vendor":"Microsoft"}]
Threat ID: 68c0bd4f9ed239a66badeb23
Added to database: 09/09/2025, 23:50:39 UTC
Last enriched: 06/10/2026, 09:48:31 UTC
Last updated: 09/10/2026, 19:36:49 UTC
Views: 129
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
External Links
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.