# CVE-2026-84393: CVE-2026-84393

Status: published. Published: 2026-09-08. Updated: 2026-11-10.

A improper validation of certificate with host mismatch vulnerability in Fortinet FortiOS 7.6.1 through 7.6.6, FortiProxy 7.6.2 through 7.6.6 may allow attacker to information disclosure via <insert attack vector here>

## Remediation

- fix: Upgrade to FortiOS version 8.0.0 or above
Upgrade to FortiOS version 7.6.7 or above
Upgrade to upcoming  FortiProxy version 8.0.0 or above
Upgrade to upcoming  FortiProxy version 7.6.7 or above
Fortinet remediated this issue in FortiSASE version 26.2.2 (not released) and hence customers do not need to perform any action. (source: CNA: fortinet)

## Affected products and versions

- Fortinet / FortiOS: ≥ 7.6.1; ≤ 7.6.6 (affected, semver). Source: CNA: fortinet
- Fortinet / FortiProxy: ≥ 7.6.2; ≤ 7.6.6 (affected, semver). Source: CNA: fortinet
- Siemens / RUGGEDCOM APE1808: ≥ 0; < * (affected, custom). Source: ADP: siemens-SADP

## Severity and prioritization

- CVSS 3.1: 7.3 (high); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C; source: CNA: fortinet

- CISA KEV: No listing in collected sources

- EPSS: 0.28% as of 2026-11-09; percentile 20.33%

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-297

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://fortiguard.fortinet.com/psirt/FG-IR-26-174 (CNA: fortinet)

- https://cert-portal.siemens.com/productcert/html/ssa-127084.html (ADP: siemens-SADP)

## Provenance

- CNA: fortinet: https://www.cve.org/CVERecord?id=CVE-2026-84393; retrieved 2026-11-10; source updated 2026-11-10

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-84393; retrieved 2026-11-10; source updated Not reported

Revision: 5a08c14ca4334775fa425ae0c38c8922c537c6487e2018c725d621e5cacf1604

Canonical: https://y2.dev/cve/CVE-2026-84393

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.