CVE-2026-62815 json
Microsoft QUIC Remote Code Execution Vulnerability
published 2026-08-11 2 mo ago modified 2026-10-30 9 d ago also GHSA-92f5-vc22-8j33 , EUVD-2026-56392
- cvss
- 9.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.0%
- EPSS 1.0% chance of exploitation in 30 days, percentile 62%
- public exploits
- 0
- none known
Summary
Use after free in Microsoft QUIC allows an unauthorized attacker to execute code over a network.
Patch / fix
- nuget Microsoft.Native.Quic.MsQuic.OpenSSL 2.4.19, 2.5.10
- nuget Microsoft.Native.Quic.MsQuic.Schannel 2.4.19, 2.5.10
- Microsoft Windows 11 version 23H2 10.0.22631.7517
- Microsoft Windows 11 Version 24H2 10.0.26100.9168
- Microsoft Windows 11 Version 25H2 10.0.26200.9168
- Microsoft Windows 11 version 26H1 10.0.28000.2704
- Microsoft Windows Server 2022 10.0.20348.5499
- Microsoft Windows Server 2025 10.0.26100.33296
- Microsoft Windows Server 2025 (Server Core installation) 10.0.26100.33296
- github.com/microsoft/msquic@583e7d5 commit
- github.com/microsoft/msquic@9ff06b7 commit
- github.com/microsoft/msquic@e0f55b5 commit
- github.com/microsoft/msquic#6217 pull request
- github.com/microsoft/msquic#6219 pull request
- github.com/microsoft/msquic#6220 pull request
- github.com/microsoft/msquic/releases/tag/v2.4.19 release
- github.com/microsoft/msquic/releases/tag/v2.5.10 release
- msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62815 advisory
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- total
- Assessed
- 3 mo ago
Exploit prediction
0.97% chance of exploitation in the next 30 days, higher than 62% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C |
| CNA | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| GitHub | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| nuget | Microsoft.Native.Quic.MsQuic.OpenSSL | >=2.5.3, <2.5.10 <2.4.19 |
2.5.10 2.4.19 |
| nuget | Microsoft.Native.Quic.MsQuic.Schannel | >=2.5.3, <2.5.10 <2.4.19 |
2.5.10 2.4.19 |
Affected products
- Microsoft Windows 11 version 23H2
- Microsoft Windows 11 Version 24H2
- Microsoft Windows 11 Version 25H2
- Microsoft Windows 11 version 26H1
- Microsoft Windows Server 2022
- Microsoft Windows Server 2025
- Microsoft Windows Server 2025 (Server Core installation)
Classification
- Weakness
-
- CWE-416 Use After Free
References
-
msrc.microsoft.com
/update-guide/vulnerability/CVE-2026-62815
vendor-advisory, patch, web
-
github.com
/microsoft/msquic/pull/6217
web
-
github.com
/microsoft/msquic/pull/6219
web
-
github.com
/microsoft/msquic/pull/6220
web
-
github.com
/microsoft/msquic/commit/583e7d5b509bb0bfa3518482d98879b6eda41ad0
web
-
github.com
/microsoft/msquic/commit/9ff06b71fd4b4d5258361598ada5b24cbc1beb20
web
-
github.com
/microsoft/msquic/commit/e0f55b5fdc9fff0b4465976d066ebd22fb7e2b3b
web
-
github.com
/microsoft/msquic/security/advisories/GHSA-92f5-vc22-8j33
web
-
nvd.nist.gov
/vuln/detail/CVE-2026-62815
advisory
-
github.com
/microsoft/msquic
package
-
github.com
/microsoft/msquic/releases/tag/v2.4.19
web
-
github.com
/microsoft/msquic/releases/tag/v2.5.10
web
Sources
- CVE List CVE-2026-62815
- GitHub Advisory GHSA-92f5-vc22-8j33
- NVD CVE-2026-62815
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.