--- id: CVE-2026-50659 title: >- Improper encoding or escaping of output in .NET allows an authorized attacker to perform spoofing over a network. summary: >- Improper encoding or escaping of output in .NET allows an authorized attacker to perform spoofing over a network. severity: medium cvss: 6.5 cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N' cwe: - CWE-116 - CWE-838 vendor: microsoft product: .net_framework affected: - .net_framework = 4.8.1 - .net_framework = 4.8 - .net_framework = 4.6.2 - .net_framework = 4.7 - .net_framework = 4.7.1 - .net_framework = 4.7.2 - '.net >= 8.0.0, < 8.0.29' - '.net >= 9.0.0, < 9.0.18' - '.net >= 10.0.0, < 10.0.6' - .net_framework = 3.5 - 'visual_studio_2022 >= 17.12.0, < 17.12.22' - 'visual_studio_2022 >= 17.14.0, < 17.14.36' - 'visual_studio_2026 >= 18.7.0, < 18.7.4' patched: - .net 10.0.6 - visual_studio_2022 17.14.36 - visual_studio_2026 18.7.4 published: '2026-07-14' updated: '2026-10-14' sourceUpdated: '2026-10-14T22:10:00.210' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-50659' references: - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50659' label: secure@microsoft.com - url: 'https://github.com/dotnet/runtime/security/advisories/GHSA-74jp-vm22-8q8x' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-50659' - url: 'https://github.com/dotnet/announcements/issues/423' - url: 'https://github.com/dotnet/runtime/issues/130716' - url: 'https://github.com/advisories/GHSA-74jp-vm22-8q8x' - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-50659.json - url: 'https://access.redhat.com/security/cve/CVE-2026-50659' - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2500589' - url: 'https://www.cve.org/CVERecord?id=CVE-2026-50659' - url: 'https://access.redhat.com/errata/RHSA-2026:58566' - url: 'https://access.redhat.com/errata/RHSA-2026:58567' - url: 'https://access.redhat.com/errata/RHSA-2026:41897' - url: 'https://access.redhat.com/errata/RHSA-2026:41893' - url: 'https://access.redhat.com/errata/RHSA-2026:41895' - url: 'https://access.redhat.com/errata/RHSA-2026:41900' - url: 'https://access.redhat.com/errata/RHSA-2026:41901' - url: 'https://access.redhat.com/errata/RHSA-2026:41899' - url: 'https://access.redhat.com/errata/RHSA-2026:58568' - url: 'https://access.redhat.com/errata/RHSA-2026:58569' - url: 'https://access.redhat.com/errata/RHSA-2026:58570' - url: 'https://access.redhat.com/errata/RHSA-2026:41898' - url: 'https://access.redhat.com/errata/RHSA-2026:41894' - url: 'https://access.redhat.com/errata/RHSA-2026:41896' - url: 'https://access.redhat.com/errata/RHSA-2026:26638' - url: 'https://access.redhat.com/errata/RHSA-2026:42145' - url: 'https://access.redhat.com/errata/RHSA-2026:39952' tags: - nvd - cve.org - ghsa - nuget - csaf - vex - red-hat ssvc: exploitation: none automatable: 'no' technicalImpact: partial timestamp: '2026-07-14T20:32:29.416499Z' epss: 0.00738 epssPercentile: 0.54648 aliases: - GHSA-74jp-vm22-8q8x ecosystem: nuget ingestedAt: '2026-07-20T23:44:02.730Z' --- ## Overview Improper encoding or escaping of output in .NET allows an authorized attacker to perform spoofing over a network. ## Affected - `.net_framework = 4.8.1` - `.net_framework = 4.8` - `.net_framework = 4.6.2` - `.net_framework = 4.7` - `.net_framework = 4.7.1` - `.net_framework = 4.7.2` - `.net >= 8.0.0, < 8.0.29` - `.net >= 9.0.0, < 9.0.18` - `.net >= 10.0.0, < 10.0.6` - `.net_framework = 3.5` - `visual_studio_2022 >= 17.12.0, < 17.12.22` - `visual_studio_2022 >= 17.14.0, < 17.14.36` - `visual_studio_2026 >= 18.7.0, < 18.7.4` ## Remediation Upgrade past the affected range: - `.net 10.0.6` - `visual_studio_2022 17.14.36` - `visual_studio_2026 18.7.4` ## Package advisory (CVE-2026-50659) Affected packages: - `Microsoft.NetCore.App.Runtime.linux-arm >= 10.0.0, <= 10.0.9` - `Microsoft.NetCore.App.Runtime.linux-arm64 >= 10.0.0, <= 10.0.9` - `Microsoft.NetCore.App.Runtime.linux-musl-arm >= 10.0.0, <= 10.0.9` - `Microsoft.NetCore.App.Runtime.linux-musl-arm64 >= 10.0.0, <= 10.0.9` - `Microsoft.NetCore.App.Runtime.linux-musl-x64 >= 10.0.0, <= 10.0.9` - `Microsoft.NetCore.App.Runtime.linux-x64 >= 10.0.0, <= 10.0.9` - `Microsoft.NetCore.App.Runtime.osx-arm64 >= 10.0.0, <= 10.0.9` - `Microsoft.NetCore.App.Runtime.osx-x64 >= 10.0.0, <= 10.0.9` - `Microsoft.NetCore.App.Runtime.win-arm >= 10.0.0, <= 10.0.9` - `Microsoft.NetCore.App.Runtime.win-arm64 >= 10.0.0, <= 10.0.9` - `Microsoft.NetCore.App.Runtime.win-x64 >= 10.0.0, <= 10.0.9` - `Microsoft.NetCore.App.Runtime.win-x86 >= 10.0.0, <= 10.0.9` - `Microsoft.NetCore.App.Runtime.linux-arm >= 9.0.0, <= 9.0.17` - `Microsoft.NetCore.App.Runtime.linux-arm64 >= 9.0.0, <= 9.0.17` - `Microsoft.NetCore.App.Runtime.linux-musl-arm >= 9.0.0, <= 9.0.17` - `Microsoft.NetCore.App.Runtime.linux-musl-arm64 >= 9.0.0, <= 9.0.17` - `Microsoft.NetCore.App.Runtime.linux-musl-x64 >= 9.0.0, <= 9.0.17` - `Microsoft.NetCore.App.Runtime.linux-x64 >= 9.0.0, <= 9.0.17` - `Microsoft.NetCore.App.Runtime.osx-arm64 >= 9.0.0, <= 9.0.17` - `Microsoft.NetCore.App.Runtime.osx-x64 >= 9.0.0, <= 9.0.17` - `Microsoft.NetCore.App.Runtime.win-arm >= 9.0.0, <= 9.0.17` - `Microsoft.NetCore.App.Runtime.win-arm64 >= 9.0.0, <= 9.0.17` - `Microsoft.NetCore.App.Runtime.win-x64 >= 9.0.0, <= 9.0.17` - `Microsoft.NetCore.App.Runtime.win-x86 >= 9.0.0, <= 9.0.17` - `Microsoft.NetCore.App.Runtime.linux-arm >= 8.0.0, <= 8.0.28` - `Microsoft.NetCore.App.Runtime.linux-arm64 >= 8.0.0, <= 8.0.28` - `Microsoft.NetCore.App.Runtime.linux-musl-arm >= 8.0.0, <= 8.0.28` - `Microsoft.NetCore.App.Runtime.linux-musl-arm64 >= 8.0.0, <= 8.0.28` - `Microsoft.NetCore.App.Runtime.linux-musl-x64 >= 8.0.0, <= 8.0.28` - `Microsoft.NetCore.App.Runtime.linux-x64 >= 8.0.0, <= 8.0.28` - `Microsoft.NetCore.App.Runtime.osx-arm64 >= 8.0.0, <= 8.0.28` - `Microsoft.NetCore.App.Runtime.osx-x64 >= 8.0.0, <= 8.0.28` - `Microsoft.NetCore.App.Runtime.win-arm >= 8.0.0, <= 8.0.28` - `Microsoft.NetCore.App.Runtime.win-arm64 >= 8.0.0, <= 8.0.28` - `Microsoft.NetCore.App.Runtime.win-x64 >= 8.0.0, <= 8.0.28` - `Microsoft.NetCore.App.Runtime.win-x86 >= 8.0.0, <= 8.0.28` Patched in: - `Microsoft.NetCore.App.Runtime.linux-arm 10.0.10` - `Microsoft.NetCore.App.Runtime.linux-arm64 10.0.10` - `Microsoft.NetCore.App.Runtime.linux-musl-arm 10.0.10` - `Microsoft.NetCore.App.Runtime.linux-musl-arm64 10.0.10` - `Microsoft.NetCore.App.Runtime.linux-musl-x64 10.0.10` - `Microsoft.NetCore.App.Runtime.linux-x64 10.0.10` - `Microsoft.NetCore.App.Runtime.osx-arm64 10.0.10` - `Microsoft.NetCore.App.Runtime.osx-x64 10.0.10` - `Microsoft.NetCore.App.Runtime.win-arm 10.0.10` - `Microsoft.NetCore.App.Runtime.win-arm64 10.0.10` - `Microsoft.NetCore.App.Runtime.win-x64 10.0.10` - `Microsoft.NetCore.App.Runtime.win-x86 10.0.10` - `Microsoft.NetCore.App.Runtime.linux-arm 9.0.18` - `Microsoft.NetCore.App.Runtime.linux-arm64 9.0.18` - `Microsoft.NetCore.App.Runtime.linux-musl-arm 9.0.18` - `Microsoft.NetCore.App.Runtime.linux-musl-arm64 9.0.18` - `Microsoft.NetCore.App.Runtime.linux-musl-x64 9.0.18` - `Microsoft.NetCore.App.Runtime.linux-x64 9.0.18` - `Microsoft.NetCore.App.Runtime.osx-arm64 9.0.18` - `Microsoft.NetCore.App.Runtime.osx-x64 9.0.18` - `Microsoft.NetCore.App.Runtime.win-arm 9.0.18` - `Microsoft.NetCore.App.Runtime.win-arm64 9.0.18` - `Microsoft.NetCore.App.Runtime.win-x64 9.0.18` - `Microsoft.NetCore.App.Runtime.win-x86 9.0.18` - `Microsoft.NetCore.App.Runtime.linux-arm 8.0.29` - `Microsoft.NetCore.App.Runtime.linux-arm64 8.0.29` - `Microsoft.NetCore.App.Runtime.linux-musl-arm 8.0.29` - `Microsoft.NetCore.App.Runtime.linux-musl-arm64 8.0.29` - `Microsoft.NetCore.App.Runtime.linux-musl-x64 8.0.29` - `Microsoft.NetCore.App.Runtime.linux-x64 8.0.29` - `Microsoft.NetCore.App.Runtime.osx-arm64 8.0.29` - `Microsoft.NetCore.App.Runtime.osx-x64 8.0.29` - `Microsoft.NetCore.App.Runtime.win-arm 8.0.29` - `Microsoft.NetCore.App.Runtime.win-arm64 8.0.29` - `Microsoft.NetCore.App.Runtime.win-x64 8.0.29` - `Microsoft.NetCore.App.Runtime.win-x86 8.0.29` Source: https://github.com/advisories/GHSA-74jp-vm22-8q8x ## Vendor advisories - **RHSA-2026:58566** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) · released 2026-08-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:58566) - **RHSA-2026:58567** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) · released 2026-08-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:58567) - **RHSA-2026:41897** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) · released 2026-07-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:41897) - **RHSA-2026:41893** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) · released 2026-07-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:41893) - **RHSA-2026:41895** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) · released 2026-07-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:41895) - **RHSA-2026:41900** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux CRB (v. 8) · released 2026-07-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:41900) - **RHSA-2026:41901** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux CRB (v. 8) · released 2026-07-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:41901) - **RHSA-2026:41899** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux CRB (v. 8) · released 2026-07-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:41899) - **RHSA-2026:58568** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.4) · released 2026-08-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:58568) - **RHSA-2026:58569** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.6), Red Hat CodeReady Linux Builder EUS (v.9.6) · released 2026-08-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:58569) - **RHSA-2026:58570** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.6), Red Hat CodeReady Linux Builder EUS (v.9.6) · released 2026-08-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:58570)