CVE-2026-59860
Code-generation injection in Kiota C# XML doc comments allowing injected C# code.
Is CVE-2026-59860 being exploited?
Not confirmed. CVE-2026-59860 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 1.4% probability of exploitation in the next 30 days.
How severe is CVE-2026-59860?
CVE-2026-59860 is rated High with a CVSS score of 8.7. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-59860?
Yes. A fix has been recorded for CVE-2026-59860. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-59860 affect?
CVE-2026-59860 affects Kiota < 1.32.3, Generated C# clients, OpenAPI specs with untrusted descriptions. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-59860?
Upgrade Kiota to >=1.32.3, regenerate and audit C# clients; sanitize OpenAPI inputs.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Malicious OpenAPI descriptions can inject arbitrary C# code into generated clients, enabling code execution when compiled/executed.
Immediate action required
- affected>= 1.30.0 and < 1.31.1
- affected< 1.29.1
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.