# CVE-2026-8451: Insufficient input validation leading to memory overread

- Exploited (CISA KEV): no
- Published: 2026-06-30
- CVSS: 8.8 HIGH (v4.0)
- EPSS: 0.5% (43th percentile)

Insufficient input validation in NetScaler ADC and NetScaler Gateway leading to memory overread if NetScaler ADC or NetScaler Gateway is configured as a SAML IDP

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

| Vendor | Status | First rule | Days after publication |
|---|---|---|---|
| Cloudflare | Blocks by default | 2026-07-14 | 14 |
| AWS | No public claim | — | — |
| Microsoft Azure | No public claim | — | — |
| Google Cloud | No public claim | — | — |
| Fastly | Before feed history | — | — |
| F5 | Rule published | 2026-09-16 | 78 |
| Akamai | No public source | — | — |
| OWASP CRS | No public claim | — | — |

### Cloudflare

- 2026-07-14 · new · rule 78826e3223b94da493a2ade876973ac4 · default Block
  > Citrix Netscaler ADC - Insufficient Input Validation - CVE:CVE-2026-8451. Previous action: Log. New action: Block. This is a new detection.
  Source: https://developers.cloudflare.com/changelog/post/2026-07-14-waf-release/

### F5

- 2026-09-16 · new · rule 200009372
  > Added: signature 200009372 "Citrix NetScaler Information Disclosure (3)" (Information Leakage, risk High), systems: Citrix. References: CVE-2026-8451.
  Source: https://docs.cloud.f5.com/docs-v2/platform/changelogs/security-details-changelog

"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-2026-8451 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2026-8451