Vulnerability · Published Oct 6, 2026 · Assigned by GitHub_M
CVE-2026-105796Kiota: Code injection through doc-comment delimiter reformation in Kiota Java and PHP generators
High 8.8
In plain English
A high-severity code injection in kiota from microsoft. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 60% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Kiota is an OpenAPI based HTTP Client code generator. From 0.5.0 until 1.35.0, Kiota's Java and PHP documentation-comment sanitizers delete block-comment terminators rather than neutralizing them, allowing overlapping characters to reform a terminator and place attacker-controlled OpenAPI text outside a generated documentation comment. The Java sanitizer also removes non-ASCII characters after deleting terminators, which can create a new terminator during normalization. Exploitation requires a developer or build pipeline to generate source from the malicious description and then compile and load the Java output or load the PHP output, after which injected code executes in the consuming application or build environment context. The version range is based on the Java defect and does not assert that PHP generation existed in every affected release. This issue is fixed in version 1.35.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| NuGet | microsoft.openapi.kiota | 1.35.0 | GHSA-rm89-rhwj-9j92 |
| NuGet | microsoft.openapi.kiota.builder | 1.35.0 | GHSA-rm89-rhwj-9j92 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| microsoft | kiota | >= 0.5.0, < 1.35.0 |
| microsoft | Microsoft.OpenApi.Kiota | >= 0.5.0, < 1.35.0 |
| microsoft | Microsoft.OpenApi.Kiota.Builder | >= 0.5.0, < 1.35.0 |
Weakness: CWE-94 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
References
- https://github.com/microsoft/kiota/security/advisories/GHSA-rm89-rhwj-9j92 x_refsource_CONFIRM
- https://github.com/microsoft/kiota/pull/8017 x_refsource_MISC
- https://github.com/microsoft/kiota/commit/68f33b865be9273464a6efbbe17379760e51f1a4 x_refsource_MISC
- https://github.com/microsoft/kiota/releases/tag/v1.35.0 x_refsource_MISC