CVE-2026-62899Medium· 5.9▾ Sunlit

.NET Security Feature Bypass Vulnerability

Inconsistent interpretation of http requests ('http request/response smuggling') in .NET allows an unauthorized attacker to bypass a security feature over a network.

▾ Sunlit zone — Low / medium · no exploitation signal

Depth score33/ 100 · Low

impact 32.5 · likelihood 0.1 · exploitation 0

⚡ Agent-ready:Raw markdown ↗JSON ↗

Proof of concept

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Published

Aug 11, 2026

Updated

Sep 16, 2026

CVSS

5.9

Vendor

Microsoft

Product

.NET 10.0

CWE

CWE-444

Depth score

33 · Low

EPSS

0.71% · p52

Platforms

—

Source

CVEORG

Vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C

CISA SSVC

decided 2026-08-12

Exploitation: none
Automatable: no
Technical impact: partial

Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake. The CVSS score shown above comes from the assigning CNA record, not NVD.

EPSS history

Exploit-prediction probability, daily snapshots since Aug 12.

0.7% → 0.7%

Timeline

Disclosure to exploitation, from the record and what we observed since indexing it.

3 events · 36 days

Aug 11, 2026Published
Disclosed via CVEORG
Aug 12, 2026EPSS first tracked
0.7%
Sep 16, 2026Record revised
Last analysed / modified upstream

Microsoft CWE-444 #cve.org #ghsa #nuget

Affected

.net_10.0 >= 10.0.0 < 10.0.11
.net_8.0 >= 8.0.0 < 8.0.30
.net_9.0 >= 9.0.0 < 9.0.19
visual_studio_2022_version_17.14 >= 17.14.0 < 17.14.38
visual_studio_2026_version_18.8 >= 18.0 < 18.8.3

Patched in

Microsoft.NETCore.App.Runtime.linux-arm 10.0.11
Microsoft.NETCore.App.Runtime.linux-arm64 10.0.11
Microsoft.NETCore.App.Runtime.linux-musl-arm 10.0.11
Microsoft.NETCore.App.Runtime.linux-musl-arm64 10.0.11
Microsoft.NETCore.App.Runtime.linux-musl-x64 10.0.11
Microsoft.NETCore.App.Runtime.linux-x64 10.0.11
Microsoft.NETCore.App.Runtime.osx-arm64 10.0.11
Microsoft.NETCore.App.Runtime.osx-x64 10.0.11
Microsoft.NETCore.App.Runtime.linux-arm 9.0.19
Microsoft.NETCore.App.Runtime.linux-arm64 9.0.19
Microsoft.NETCore.App.Runtime.linux-musl-arm 9.0.19
Microsoft.NETCore.App.Runtime.linux-musl-arm64 9.0.19
Microsoft.NETCore.App.Runtime.linux-musl-x64 9.0.19
Microsoft.NETCore.App.Runtime.linux-x64 9.0.19
Microsoft.NETCore.App.Runtime.osx-arm64 9.0.19
Microsoft.NETCore.App.Runtime.osx-x64 9.0.19
Microsoft.NETCore.App.Runtime.linux-arm 8.0.30
Microsoft.NETCore.App.Runtime.linux-arm64 8.0.30
Microsoft.NETCore.App.Runtime.linux-musl-arm 8.0.30
Microsoft.NETCore.App.Runtime.linux-musl-arm64 8.0.30
Microsoft.NETCore.App.Runtime.linux-musl-x64 8.0.30
Microsoft.NETCore.App.Runtime.linux-x64 8.0.30
Microsoft.NETCore.App.Runtime.osx-arm64 8.0.30
Microsoft.NETCore.App.Runtime.osx-x64 8.0.30

Full technical detail▾

Overview

Inconsistent interpretation of http requests ('http request/response smuggling') in .NET allows an unauthorized attacker to bypass a security feature over a network.

Affected

.net_10.0 >= 10.0.0 < 10.0.11
.net_8.0 >= 8.0.0 < 8.0.30
.net_9.0 >= 9.0.0 < 9.0.19
visual_studio_2022_version_17.14 >= 17.14.0 < 17.14.38
visual_studio_2026_version_18.8 >= 18.0 < 18.8.3

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

Package advisory (CVE-2026-62899)

Affected packages:

Microsoft.NETCore.App.Runtime.linux-arm >= 10.0.0, <= 10.0.10
Microsoft.NETCore.App.Runtime.linux-arm64 >= 10.0.0, <= 10.0.10
Microsoft.NETCore.App.Runtime.linux-musl-arm >= 10.0.0, <= 10.0.10
Microsoft.NETCore.App.Runtime.linux-musl-arm64 >= 10.0.0, <= 10.0.10
Microsoft.NETCore.App.Runtime.linux-musl-x64 >= 10.0.0, <= 10.0.10
Microsoft.NETCore.App.Runtime.linux-x64 >= 10.0.0, <= 10.0.10
Microsoft.NETCore.App.Runtime.osx-arm64 >= 10.0.0, <= 10.0.10
Microsoft.NETCore.App.Runtime.osx-x64 >= 10.0.0, <= 10.0.10
Microsoft.NETCore.App.Runtime.linux-arm >= 9.0.0, <= 9.0.18
Microsoft.NETCore.App.Runtime.linux-arm64 >= 9.0.0, <= 9.0.18
Microsoft.NETCore.App.Runtime.linux-musl-arm >= 9.0.0, <= 9.0.18
Microsoft.NETCore.App.Runtime.linux-musl-arm64 >= 9.0.0, <= 9.0.18
Microsoft.NETCore.App.Runtime.linux-musl-x64 >= 9.0.0, <= 9.0.18
Microsoft.NETCore.App.Runtime.linux-x64 >= 9.0.0, <= 9.0.18
Microsoft.NETCore.App.Runtime.osx-arm64 >= 9.0.0, <= 9.0.18
Microsoft.NETCore.App.Runtime.osx-x64 >= 9.0.0, <= 9.0.18
Microsoft.NETCore.App.Runtime.linux-arm >= 8.0.0, <= 8.0.29
Microsoft.NETCore.App.Runtime.linux-arm64 >= 8.0.0, <= 8.0.29
Microsoft.NETCore.App.Runtime.linux-musl-arm >= 8.0.0, <= 8.0.29
Microsoft.NETCore.App.Runtime.linux-musl-arm64 >= 8.0.0, <= 8.0.29
Microsoft.NETCore.App.Runtime.linux-musl-x64 >= 8.0.0, <= 8.0.29
Microsoft.NETCore.App.Runtime.linux-x64 >= 8.0.0, <= 8.0.29
Microsoft.NETCore.App.Runtime.osx-arm64 >= 8.0.0, <= 8.0.29
Microsoft.NETCore.App.Runtime.osx-x64 >= 8.0.0, <= 8.0.29

Patched in:

Microsoft.NETCore.App.Runtime.linux-arm 10.0.11
Microsoft.NETCore.App.Runtime.linux-arm64 10.0.11
Microsoft.NETCore.App.Runtime.linux-musl-arm 10.0.11
Microsoft.NETCore.App.Runtime.linux-musl-arm64 10.0.11
Microsoft.NETCore.App.Runtime.linux-musl-x64 10.0.11
Microsoft.NETCore.App.Runtime.linux-x64 10.0.11
Microsoft.NETCore.App.Runtime.osx-arm64 10.0.11
Microsoft.NETCore.App.Runtime.osx-x64 10.0.11
Microsoft.NETCore.App.Runtime.linux-arm 9.0.19
Microsoft.NETCore.App.Runtime.linux-arm64 9.0.19
Microsoft.NETCore.App.Runtime.linux-musl-arm 9.0.19
Microsoft.NETCore.App.Runtime.linux-musl-arm64 9.0.19
Microsoft.NETCore.App.Runtime.linux-musl-x64 9.0.19
Microsoft.NETCore.App.Runtime.linux-x64 9.0.19
Microsoft.NETCore.App.Runtime.osx-arm64 9.0.19
Microsoft.NETCore.App.Runtime.osx-x64 9.0.19
Microsoft.NETCore.App.Runtime.linux-arm 8.0.30
Microsoft.NETCore.App.Runtime.linux-arm64 8.0.30
Microsoft.NETCore.App.Runtime.linux-musl-arm 8.0.30
Microsoft.NETCore.App.Runtime.linux-musl-arm64 8.0.30
Microsoft.NETCore.App.Runtime.linux-musl-x64 8.0.30
Microsoft.NETCore.App.Runtime.linux-x64 8.0.30
Microsoft.NETCore.App.Runtime.osx-arm64 8.0.30
Microsoft.NETCore.App.Runtime.osx-x64 8.0.30

Source: https://github.com/advisories/GHSA-r6mh-95jw-g7qg

References

Related vulnerabilities

Connected by shared product, vendor, weakness, or advisory.

#cve.org#ghsa#nuget

Package advisory (CVE-2026-62899)

Affected packages:

Microsoft.NETCore.App.Runtime.linux-arm >= 10.0.0, <= 10.0.10

Microsoft.NETCore.App.Runtime.linux-arm64 >= 10.0.0, <= 10.0.10

Microsoft.NETCore.App.Runtime.linux-musl-arm >= 10.0.0, <= 10.0.10

Microsoft.NETCore.App.Runtime.linux-musl-arm64 >= 10.0.0, <= 10.0.10

Microsoft.NETCore.App.Runtime.linux-musl-x64 >= 10.0.0, <= 10.0.10

Microsoft.NETCore.App.Runtime.linux-x64 >= 10.0.0, <= 10.0.10

Microsoft.NETCore.App.Runtime.osx-arm64 >= 10.0.0, <= 10.0.10

Microsoft.NETCore.App.Runtime.osx-x64 >= 10.0.0, <= 10.0.10

Microsoft.NETCore.App.Runtime.linux-arm >= 9.0.0, <= 9.0.18

Microsoft.NETCore.App.Runtime.linux-arm64 >= 9.0.0, <= 9.0.18

Microsoft.NETCore.App.Runtime.linux-musl-arm >= 9.0.0, <= 9.0.18

Microsoft.NETCore.App.Runtime.linux-musl-arm64 >= 9.0.0, <= 9.0.18

Microsoft.NETCore.App.Runtime.linux-musl-x64 >= 9.0.0, <= 9.0.18

Microsoft.NETCore.App.Runtime.linux-x64 >= 9.0.0, <= 9.0.18

Microsoft.NETCore.App.Runtime.osx-arm64 >= 9.0.0, <= 9.0.18

Microsoft.NETCore.App.Runtime.osx-x64 >= 9.0.0, <= 9.0.18

Microsoft.NETCore.App.Runtime.linux-arm >= 8.0.0, <= 8.0.29

Microsoft.NETCore.App.Runtime.linux-arm64 >= 8.0.0, <= 8.0.29

Microsoft.NETCore.App.Runtime.linux-musl-arm >= 8.0.0, <= 8.0.29

Microsoft.NETCore.App.Runtime.linux-musl-arm64 >= 8.0.0, <= 8.0.29

Microsoft.NETCore.App.Runtime.linux-musl-x64 >= 8.0.0, <= 8.0.29

Microsoft.NETCore.App.Runtime.linux-x64 >= 8.0.0, <= 8.0.29

Microsoft.NETCore.App.Runtime.osx-arm64 >= 8.0.0, <= 8.0.29

Microsoft.NETCore.App.Runtime.osx-x64 >= 8.0.0, <= 8.0.29

Patched in:

Microsoft.NETCore.App.Runtime.linux-arm 10.0.11

Microsoft.NETCore.App.Runtime.linux-arm64 10.0.11

Microsoft.NETCore.App.Runtime.linux-musl-arm 10.0.11

Microsoft.NETCore.App.Runtime.linux-musl-arm64 10.0.11

Microsoft.NETCore.App.Runtime.linux-musl-x64 10.0.11

Microsoft.NETCore.App.Runtime.linux-x64 10.0.11

Microsoft.NETCore.App.Runtime.osx-arm64 10.0.11

Microsoft.NETCore.App.Runtime.osx-x64 10.0.11

Microsoft.NETCore.App.Runtime.linux-arm 9.0.19

Microsoft.NETCore.App.Runtime.linux-arm64 9.0.19

Microsoft.NETCore.App.Runtime.linux-musl-arm 9.0.19

Microsoft.NETCore.App.Runtime.linux-musl-arm64 9.0.19

Microsoft.NETCore.App.Runtime.linux-musl-x64 9.0.19

Microsoft.NETCore.App.Runtime.linux-x64 9.0.19

Microsoft.NETCore.App.Runtime.osx-arm64 9.0.19

Microsoft.NETCore.App.Runtime.osx-x64 9.0.19

Microsoft.NETCore.App.Runtime.linux-arm 8.0.30

Microsoft.NETCore.App.Runtime.linux-arm64 8.0.30

Microsoft.NETCore.App.Runtime.linux-musl-arm 8.0.30

Microsoft.NETCore.App.Runtime.linux-musl-arm64 8.0.30

Microsoft.NETCore.App.Runtime.linux-musl-x64 8.0.30

Microsoft.NETCore.App.Runtime.linux-x64 8.0.30

Microsoft.NETCore.App.Runtime.osx-arm64 8.0.30

Microsoft.NETCore.App.Runtime.osx-x64 8.0.30