Intel

CVE-2026-62815

microsoft.native.quic.msquic.openssl: Use After Free (CVE-2026-62815)

criticalEPSS 1.0%

Affected

  • nuget/microsoft.native.quic.msquic.openssl 2.5.3..*
  • nuget/microsoft.native.quic.msquic.schannel 2.5.3..*
  • nuget/microsoft.native.quic.msquic.openssl 1.8.0..*
  • nuget/microsoft.native.quic.msquic.schannel 1.8.0..*

Description

Use after free in Microsoft QUIC allows an unauthorized attacker to execute code over a network.

Source: OSV (Open Source Vulnerabilities)GitHub Security Advisoriescvelistv5NVD (NIST)Microsoft Security Update GuideBSI WID PortalBSI CSAF

Affected operating systems

  • windows

    microsoft / windows_11_23h2

  • windows

    microsoft / windows_11_24h2

  • windows

    microsoft / windows_11_25h2

  • windows

    microsoft / windows_11_26h1

  • windows

    microsoft / windows_server_2022

  • windows

    microsoft / windows_server_2025

Affected products

The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

nugetmicrosoft.native.quic.msquic.openssl
1.8.02.5.3
nugetmicrosoft.native.quic.msquic.schannel
1.8.02.5.3

Metrics

XIEM Effective CVSS
9.8
Source: nvd-v3
EPSS percentile
61.0 %
High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
KEV status
—
Show all metrics
Severity
critical
Priority score
108.41
Exploit maturity
no public PoC known
CVSS v3
9.8
EPSS score
1.0 %
Low — model estimates < 1% exploitation likelihood.
Published
2026-09-08 20:27 UTC
CWE
CWE-416

Weakness classes (CWE)

  • CWE-416Variant

    Use After Free

    The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

    cwe.mitre.org →

References & sources

Reanalysis & status changes

Chronological NVD audit events for this CVE — reanalyses, CVSS updates, CPE diffs.

  1. CVE Modified2026-08-11 20:18 UTC· 134c704f-9b21-4f2e-91b3-4a467353bcc0
    • SSVC: {"id":"CVE-2026-62815","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"yes"},{"technical…
  2. New CVE Received2026-08-11 17:18 UTC· secure@microsoft.com
    • Affected: Windows 11 version 23H2, Windows 11 Version 23H2, Windows 11 Version 24H2 (+5)
    • Description: Use after free in Microsoft QUIC allows an unauthorized attacker to execute code over a network.
    • CVSS V3.1: AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    • CWE: CWE-416

Linked advisories