MicrosoftCVE-2026-50517
Microsoft 365 Copilot: unsafe deserialization
Critical9.9CVE-2026-50517 · Published Jul 24, 2026 · updated Jul 29, 2026
Deserialization of untrusted data in M365 Copilot allows an authorized attacker to execute code over a network.
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| Microsoft 365 Copilot Product | all versions | No fix yet |
Details and references
- CVSS 3.1
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- Severity from
- the vendor (its own CVE record or advisory)
- Weakness
- CWE-502
More Microsoft advisories
All Microsoft| Date | Advisory | Severity | Fixed in |
|---|---|---|---|
| Jul 24 | Microsoft Azure Portal: improper authorization | Critical9.3 | No fix yet |
| Jul 24 | Microsoft Azure App Service for Linux: improper access control | Critical10.0 | No fix yet |
| Jul 24 | Microsoft Purview Data Governance: server-side request forgery | Critical10.0 | No fix yet |
| Jul 24 | Microsoft Azure Kubernetes Service: missing authentication | Critical10.0 | No fix yet |
| Jul 24 | Microsoft Azure Key Vault: improper authentication | Critical10.0 | No fix yet |
| Jul 24 | Microsoft Azure DNS: missing authorization | Critical10.0 | No fix yet |