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CVE-2026-62898 Microsoft CVE debrief

Microsoft QUIC Information Disclosure Vulnerability debrief. This vulnerability, identified as CVE-2026-62898, is a use-after-free issue in Microsoft QUIC that allows unauthorized attackers to disclose information over a network. The vulnerability affects .NET and Visual Studio deployments, requiring administrators to assess exposure and apply patches. The CVE record and NVD entry provide details on the vulnerability, and the Microsoft Security Response Center (MSRC) has an advisory for this vulnerability.

Vendor
Microsoft
Product
.NET 10.0
CVSS
HIGH 7.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-08-11
Original CVE updated
2026-10-08
Advisory published
2026-08-11
Advisory updated
2026-10-08

Who should care

Administrators of .NET and Visual Studio deployments should assess exposure and apply patches. This vulnerability allows unauthorized attackers to disclose information over a network, potentially leading to information disclosure. Affected operators, platforms, vulnerability-management, and security teams should review and apply patches for .NET 10.0, .NET 8.0, .NET 9.0, Microsoft Visual Studio 2022 version 17.14, 18

Why it matters

This vulnerability allows an unauthorized attacker to disclose information over a network. .NET and Visual Studio administrators should assess exposure and apply patches.

  • Potential information disclosure over the network
  • Requires verification of affected versions and exposure
  • Patching is recommended to prevent potential exploitation

Technical summary

The Microsoft QUIC Information Disclosure Vulnerability is a use-after-free vulnerability in Microsoft QUIC that allows an unauthorized attacker to disclose information over a network. This vulnerability affects .NET and Visual Studio deployments. Administrators should assess exposure and apply patches to prevent potential exploitation. The vulnerability has a CVSS score of 7.5 and is considered HIGH severity.

Defensive priority

High priority for .NET and Visual Studio administrators

Recommended defensive actions

  • Review and apply patches for .NET 10.0, .NET 8.0, .NET 9.0, Microsoft Visual Studio 2022 version 17.14, and Microsoft Visual Studio 2026 version 18.8
  • Update affected systems to versions 10.0.11, 8.0.30, 9.0.19, 17.14.38, and 18.8.3 or later
  • Verify inventory of .NET and Visual Studio deployments for exposure

Evidence notes

The CVE record and NVD entry provide details on the vulnerability. The Microsoft Security Response Center (MSRC) has an advisory for this vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-62898 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-62898

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-62898 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-62898

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Microsoft QUIC Information Disclosure Vulnerability

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/62xxx/CVE-2026-62898.json

    cve_program_cvelist_v5

  • Source reference

    Unverified legacy reference

    URL: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62898

    Supplemental source - vendor-advisory, patch

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.