CVE-2026-62898Network attack vector

Unauthenticated information disclosure via use-after-free

Published Aug 11, 2026 · Updated Aug 25, 2026

Use-after-free in Microsoft QUIC in affected .NET and Visual Studio releases allows remote attackers to disclose information over a network. Microsoft has not published the allocation, lifetime transition, or QUIC message that leaves the freed object reachable. Exploitation requires an unauthenticated network path to a Windows application using the affected runtime; the documented impact excludes data modification and service interruption.

CVSS severity7.5
High
EPSS probability1.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Microsoft QUIC in affected .NET and Visual Studio releases allows remote attackers to disclose information over a network. Microsoft has not published the allocation, lifetime transition, or QUIC message that leaves the freed object reachable. Exploitation requires an unauthenticated network path to a Windows application using the affected runtime; the documented impact excludes data modification and service interruption.

The record

CVE
CVE-2026-62898
Published
Aug 11, 2026
Updated
Aug 25, 2026
Vendor
Microsoft
Product
.NET 9.0
Classifications
CWE-416, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 25, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=9.0.0 <9.0.19

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · .NET 9.0version=9.0.0 <9.0.19
Microsoft · .NET 10.0version=10.0.0 <10.0.11
Microsoft · Microsoft Visual Studio 2022 version 17.14version=17.14.0 <17.14.38
Microsoft · .NET 8.0version=8.0.0 <8.0.30
Microsoft · Microsoft Visual Studio 2026 version 18.8version=18.0 <18.8.3

Published CVSS scores

7.5CanonicalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
7.5MicrosoftCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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