# CVE-2026-50522: Microsoft SharePoint Deserialization of Untrusted Data Vulnerability 

- Exploited (CISA KEV): yes, added 2026-07-22
- Published: 2026-07-14
- CVSS: 9.8 CRITICAL (v3.1)
- EPSS: 3.0% (88th percentile)
- CWE: CWE-502

Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.

## Edge WAF coverage (claimed by vendors, not measured)

| Vendor | Status | First rule | Days after publication |
|---|---|---|---|
| Cloudflare | Blocks by default | 2026-08-04 | 21 |
| AWS | No public claim | — | — |
| Microsoft Azure | No public claim | — | — |
| Google Cloud | No public claim | — | — |
| Fastly | Before feed history | — | — |
| F5 | No public claim | — | — |
| Akamai | No public source | — | — |
| OWASP CRS | No public claim | — | — |

### Cloudflare

- 2026-08-04 · new · rule 91aee93c31944828bf86f068052b07cf · default Block
  > Microsoft SharePoint - Remote Code Execution - CVE:CVE-2026-50522. Previous action: Log. New action: Block. This is a new detection.
  Source: https://developers.cloudflare.com/changelog/post/2026-08-04-waf-release/

"No public claim" means no vendor statement names this CVE; "Before feed history" means the CVE is older than the vendor feed. In both cases generic rules may still block it.

HTML: https://cve.vigilbase.com/cve/CVE-2026-50522 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2026-50522