Microsoft Security Advisory CVE-2026-57108 – .NET Denial of Service Vulnerability

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-57108: 1.17% estimated exploitation activity in the next 30 days; percentile 67.57 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Executive summary Microsoft is releasing this security advisory to provide information about a vulnerability in the .NET runtime cryptography layer (CryptoNative_GetX509NameInfo). This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in the .NET 8, .NET 9, and .NET 10 runtime when parsing X.509 certificates. A specially crafted certificate could allow an attacker to cause a denial of service.

Announcement Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/408

CVSS Details - Version: 3.1 - Severity: High - Score: 7.5 - Vector: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H` - Weakness: CWE-843 (Access of Resource Using Incompatible Type ('Type Confusion'))

Affected Platforms - Platforms: Linux, macOS - Architectures: All

Affected Packages The vulnerability affects any Microsoft .NET project if it…

Published by the source

20 Jul 2026, 22:41 UTC

Last modified by the source

4 Nov 2026, 04:15 UTC

Source last checked

4 Nov 2026, 06:40 UTC

1. Revision 3 · amended · 4 Nov 2026

   Amended from osv record GHSA-rp2p-6cmp-jxj9

2. Revision 2 · amended · 4 Nov 2026

   Amended from ghsa record GHSA-rp2p-6cmp-jxj9

3. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-rp2p-6cmp-jxj9

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# Patch Next advisory brief: CVE-2026-57108

Advisory: Microsoft Security Advisory CVE-2026-57108 – .NET Denial of Service Vulnerability
IDs: CVE-2026-57108, GHSA-rp2p-6cmp-jxj9
Record: https://patchnext.com/advisories/cve-2026-57108 (revision 3, source checked 4 Nov 2026, 06:40 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: microsoft.netcore.app.runtime.linux-musl-x64 10.0.10, 9.0.18, 8.0.29; microsoft.netcore.app.runtime.linux-arm64 10.0.10, 9.0.18, 8.0.29; microsoft.netcore.app.runtime.linux-arm 10.0.10, 9.0.18, 8.0.29; microsoft.netcore.app.runtime.osx-x64 10.0.10, 9.0.18, 8.0.29; microsoft.netcore.app.runtime.linux-x64 10.0.10, 9.0.18, 8.0.29; microsoft.netcore.app.runtime.osx-arm64 10.0.10, 9.0.18, 8.0.29; microsoft.netcore.app.runtime.linux-musl-arm 10.0.10, 9.0.18, 8.0.29; microsoft.netcore.app.runtime.linux-musl-arm64 10.0.10, 9.0.18, 8.0.29. A vendor fix does not mean a deployment is fixed.

## Affected components
- NuGet microsoft.netcore.app.runtime.linux-musl-x64: affected >= 10.0.0, < 10.0.10; >= 9.0.0, < 9.0.18; >= 8.0.0, < 8.0.29; fixed in 8.0.29, 10.0.10, 9.0.18
- NuGet microsoft.netcore.app.runtime.linux-arm64: affected >= 10.0.0, < 10.0.10; >= 9.0.0, < 9.0.18; >= 8.0.0, < 8.0.29; fixed in 8.0.29, 10.0.10, 9.0.18
- NuGet microsoft.netcore.app.runtime.linux-arm: affected >= 10.0.0, < 10.0.10; >= 9.0.0, < 9.0.18; >= 8.0.0, < 8.0.29; fixed in 8.0.29, 10.0.10, 9.0.18
- NuGet microsoft.netcore.app.runtime.osx-x64: affected >= 10.0.0, < 10.0.10; >= 9.0.0, < 9.0.18; >= 8.0.0, < 8.0.29; fixed in 8.0.29, 10.0.10, 9.0.18
- NuGet microsoft.netcore.app.runtime.linux-x64: affected >= 10.0.0, < 10.0.10; >= 9.0.0, < 9.0.18; >= 8.0.0, < 8.0.29; fixed in 8.0.29, 10.0.10, 9.0.18
- NuGet microsoft.netcore.app.runtime.osx-arm64: affected >= 10.0.0, < 10.0.10; >= 9.0.0, < 9.0.18; >= 8.0.0, < 8.0.29; fixed in 8.0.29, 10.0.10, 9.0.18
- NuGet microsoft.netcore.app.runtime.linux-musl-arm: affected >= 10.0.0, < 10.0.10; >= 9.0.0, < 9.0.18; >= 8.0.0, < 8.0.29; fixed in 8.0.29, 10.0.10, 9.0.18
- NuGet microsoft.netcore.app.runtime.linux-musl-arm64: affected >= 10.0.0, < 10.0.10; >= 9.0.0, < 9.0.18; >= 8.0.0, < 8.0.29; fixed in 8.0.29, 10.0.10, 9.0.18

## Suggested inspection (read-only)
- NuGet microsoft.netcore.app.runtime.linux-musl-x64: check the installed version with your package manager.
- NuGet microsoft.netcore.app.runtime.linux-arm64: check the installed version with your package manager.
- NuGet microsoft.netcore.app.runtime.linux-arm: check the installed version with your package manager.
- NuGet microsoft.netcore.app.runtime.osx-x64: check the installed version with your package manager.
- NuGet microsoft.netcore.app.runtime.linux-x64: check the installed version with your package manager.
- NuGet microsoft.netcore.app.runtime.osx-arm64: check the installed version with your package manager.
- NuGet microsoft.netcore.app.runtime.linux-musl-arm: check the installed version with your package manager.
- NuGet microsoft.netcore.app.runtime.linux-musl-arm64: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on microsoft.netcore.app.runtime.linux-musl-x64, microsoft.netcore.app.runtime.linux-arm64, microsoft.netcore.app.runtime.linux-arm, microsoft.netcore.app.runtime.osx-x64, microsoft.netcore.app.runtime.linux-x64, microsoft.netcore.app.runtime.osx-arm64, microsoft.netcore.app.runtime.linux-musl-arm, microsoft.netcore.app.runtime.linux-musl-arm64.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-rp2p-6cmp-jxj9 (GitHub-reviewed advisory GHSA-rp2p-6cmp-jxj9 lists affected ranges: NuGet microsoft.netcore.app.runtime.linux-arm >=10.0.0 =9.0.0 =8.0.0 =10.0.0 =9.0.0 =8.0.0 =10.0.0 =9.0.0 =8.0.0 =10.0.0 =9.0.0 =8.0.0 <=8.0.28; NuGet…)
- Verified: https://osv.dev/vulnerability/GHSA-rp2p-6cmp-jxj9 (OSV record GHSA-rp2p-6cmp-jxj9 lists affected ranges: NuGet microsoft.netcore.app.runtime.linux-arm >=10.0.0 =9.0.0 =8.0.0 =10.0.0 =9.0.0 =8.0.0 =10.0.0 =9.0.0 =8.0.0 =10.0.0…)

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