All vulnerabilities
CVE-2026-105796GHSA-rm89-rhwj-9j92

Microsoft.OpenApi.Kiota: Kiota: Code injection through doc-comment delimiter reformation in Kiota Java and PHP generators

microsoft Microsoft.OpenApi.KiotanugetLibraries & packages
Open in ThreatlineRecord JSON
CVSS
8.8High
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.90%Chance of exploitation activity in the next 30 days, higher than 59% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in1.35.0Fixed versionGitHub
Published6 Oct 2026Updated 9 Oct 2026CVE List

What fixes it

  • 1.35.0Microsoft.OpenApi.Kiota, nugetGitHubdotnet add package Microsoft.OpenApi.Kiota --version 1.35.0
  • 1.35.0Microsoft.OpenApi.Kiota.Builder, nugetGitHubdotnet add package Microsoft.OpenApi.Kiota.Builder --version 1.35.0
  • 1.35.0Microsoft.OpenApi.Kiota, NuGetOSVdotnet add package Microsoft.OpenApi.Kiota --version 1.35.0
  • 1.35.0Microsoft.OpenApi.Kiota.Builder, NuGetOSVdotnet add package Microsoft.OpenApi.Kiota.Builder --version 1.35.0

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

Impact

An attacker who controls or tampers with an OpenAPI description can cause Kiota to emit attacker-controlled Java or PHP source outside a generated documentation comment. The affected sanitizers remove comment terminators rather than neutralizing them, allowing a terminator to reform from overlapping characters or from subsequent normalization. The Java sanitizer also removes non-ASCII characters after removing terminators, which can create a new terminator.

Exploitation requires a developer or build pipeline to generate a client from the malicious description and subsequently compile and load the Java output, or load the PHP output. Code executes in the consuming application's or build environment's security context, not merely because Kiota reads the description.

Affected versions

The affected NuGet packages are Microsoft.OpenApi.Kiota and Microsoft.OpenApi.Kiota.Builder. The Java normalization-order defect was introduced in version 0.5.0 and remains present through version 1.34.1, including the separate 1.29.1 security-backport release. The PHP delimiter-reformation variant is also present in version 1.34.1 and 1.29.1. Version 1.35.0 fixes both variants.

The package version range below reflects the Java defect; it does not assert that PHP generation existed in every version in that range.

Patches

Upgrade to Kiota 1.35.0 or later and regenerate affected clients. The fix neutralizes block-comment delimiters instead of deleting them, and performs Java delimiter neutralization after non-ASCII normalization.

  • Fix: https://github.com/microsoft/kiota/pull/8017
  • Fixed release: https://github.com/microsoft/kiota/releases/tag/v1.35.0

Workarounds

Until upgrading, generate clients only from trusted, integrity-protected OpenAPI descriptions. Review generated Java and PHP source before compiling, loading, or deploying it. Restrict the privileges and secrets available to generation and build environments.

Related advisories

This is distinct from PHP double-quoted string interpolation (GHSA-jqwh-526h-c92j) and C# XML documentation newline breakout (GHSA-3hrf-2gc2-mx32). Those fixes do not address Java/PHP block-comment delimiter reformation.

Text from GitHub Advisory Database

Affected versions 99

  • Microsoft.OpenApi.Kiota, nuget>= 0.5.0, < 1.35.0GitHub
  • Microsoft.OpenApi.Kiota.Builder, nuget>= 0.5.0, < 1.35.0GitHub
  • kiotaaffected: >= 0.5.0, < 1.35.0CVE List
  • Microsoft.OpenApi.Kiotaaffected: >= 0.5.0, < 1.35.0CVE List
  • Microsoft.OpenApi.Kiota.Builderaffected: >= 0.5.0, < 1.35.0CVE List
  • Microsoft.OpenApi.Kiota, NuGetfrom 0.5.0, fixed in 1.35.0OSV
  • Microsoft.OpenApi.Kiota, NuGet0.10.0-previewOSV
  • Microsoft.OpenApi.Kiota, NuGet0.11.0-previewOSV
  • Microsoft.OpenApi.Kiota, NuGet0.11.1-previewOSV
  • Microsoft.OpenApi.Kiota, NuGet0.5.1-previewOSV
  • Microsoft.OpenApi.Kiota, NuGet0.6.0-previewOSV
  • Microsoft.OpenApi.Kiota, NuGet0.7.1-previewOSV
  • Microsoft.OpenApi.Kiota, NuGet0.8.3-previewOSV
  • Microsoft.OpenApi.Kiota, NuGet0.9.0-previewOSV
  • Microsoft.OpenApi.Kiota, NuGet1.0.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.0.1OSV
  • Microsoft.OpenApi.Kiota, NuGet1.1.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.1.1OSV
  • Microsoft.OpenApi.Kiota, NuGet1.1.2OSV
  • Microsoft.OpenApi.Kiota, NuGet1.1.3OSV
  • Microsoft.OpenApi.Kiota, NuGet1.10.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.10.1OSV
  • Microsoft.OpenApi.Kiota, NuGet1.11.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.11.1OSV
  • Microsoft.OpenApi.Kiota, NuGet1.12.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.13.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.14.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.15.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.16.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.17.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.18.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.19.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.19.1OSV
  • Microsoft.OpenApi.Kiota, NuGet1.2.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.2.1OSV
  • Microsoft.OpenApi.Kiota, NuGet1.20.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.21.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.22.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.22.1OSV
  • Microsoft.OpenApi.Kiota, NuGet1.22.2OSV
  • Microsoft.OpenApi.Kiota, NuGet1.22.3OSV
  • Microsoft.OpenApi.Kiota, NuGet1.23.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.24.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.24.1OSV
  • Microsoft.OpenApi.Kiota, NuGet1.24.2OSV
  • Microsoft.OpenApi.Kiota, NuGet1.24.3OSV
  • Microsoft.OpenApi.Kiota, NuGet1.25.1OSV
  • Microsoft.OpenApi.Kiota, NuGet1.26.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.26.1OSV
  • Microsoft.OpenApi.Kiota, NuGet1.27.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.28.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.29.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.29.1OSV
  • Microsoft.OpenApi.Kiota, NuGet1.3.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.30.0OSV
  • Microsoft.OpenApi.Kiota, NuGet1.31.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGetfrom 0.5.0, fixed in 1.35.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet0.5.1-previewOSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet0.6.0-previewOSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet0.7.1-previewOSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.0.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.0.1OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.1.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.1.1OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.1.2OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.1.3OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.10.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.10.1OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.11.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.11.1OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.12.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.13.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.14.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.15.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.16.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.17.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.18.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.19.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.19.1OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.2.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.2.1OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.20.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.21.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.22.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.22.1OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.22.2OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.22.3OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.23.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.3.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.4.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.5.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.5.1OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.6.1OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.7.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.8.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.8.1OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.8.2OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.9.0OSV
  • Microsoft.OpenApi.Kiota.Builder, NuGet1.9.1OSV

References 6