CVE-2026-59866: critical vulnerability in microsoft kiota
Kiota: Arbitrary file write + code-injection via x-ms-kiota-info clientClassName and clientNamespaceName
Published · Updated
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28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 9.3epss 1.4%
Kiota is an OpenAPI based HTTP Client code generator. Prior to 1.29.1 and 1.32.5, Kiota emitted x-ms-kiota-info clientClassName and clientNamespaceName values without identifier or path sanitization as both generated client class or namespace names and generated output path components when `kiota generate` ran without -c/--class-name, allowing an attacker-controlled or compromised OpenAPI description to write generated source outside the -o output directory and inject arbitrary text into generated class or namespace declarations. This issue is fixed in version 1.29.1 and 1.32.5 by GenerationConfiguration.SanitizeClientClassName and SanitizeClientNamespaceName.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Affected products
microsoft · kiotaRelated CVEs — microsoft kiota
In the same product, most dangerous first.
CVE-2026-59865CRITICALKiota: Command injection via x-ms-kiota-info dependencyInstallCommand surfaced by `kiota info`EPSS 4.4%CVE-2026-59867HIGHKiota: Generation-time SSRF + remote/local file inclusion via unrestricted $refEPSS 2.4%CVE-2026-73851MEDIUMKiota: Path traversal in generated plugin manifest static_template.file reference (percent-encoding bypass)EPSS 2.3%CVE-2026-59861HIGHKiota: Code Generation Literal Injection in Kiota Ruby GeneratorEPSS 2.0%CVE-2026-59859HIGHKiota: Code Generation Literal Injection in the PHP GeneratorEPSS 1.4%CVE-2026-59860HIGHKiota: XML Doc-Comment Newline Breakout Code InjectionEPSS 1.4%