# CVE-2026-71407: CVE-2026-71407

Status: published. Published: 2026-08-12. Updated: 2026-11-10.

A Stack-based Buffer Overflow vulnerability [CWE-121] vulnerability in Fortinet FortiOS 7.6.1 through 7.6.6 may allow an unauthenticated attacker who can bypass stack protection and ASLR to execute arbitrary code or commands in the context of the WAD daemon via crafted sockets, only if the explicit proxy is configured with Kerberos authentication and SOCKS enabled.

## Remediation

- fix: Upgrade to FortiOS version 8.0.0 or above
Upgrade to FortiOS version 7.6.7 or above (source: CNA: fortinet)

## Affected products and versions

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

## NVD configuration conditions

Affected CPE matches depend on the following AND/OR and negation conditions:

```json
[
  {
    "negate": false,
    "nodes": [
      {
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "7.6.7",
            "versionStartIncluding": "7.6.1",
            "vulnerable": true
          }
        ],
        "negate": false,
        "operator": "OR"
      }
    ],
    "operator": "OR"
  }
]
```

## Severity and prioritization

- CVSS 3.1: 5.1 (medium); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C; source: CNA: fortinet

- CVSS 3.1: 8.1 (high); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H; source: NVD: nvd@nist.gov

- CVSS 3.1: 5.6 (medium); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L; source: NVD: psirt@fortinet.com

- CISA KEV: No listing in collected sources

- EPSS: 0.51% as of 2026-11-09; percentile 44.08%

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

- Weaknesses: CWE-121

## Exploit evidence

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

## References

- https://fortiguard.fortinet.com/psirt/FG-IR-26-161 (CNA: fortinet)

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

- https://fortiguard.fortinet.com/psirt/FG-IR-26-161 (psirt@fortinet.com; Vendor Advisory)

- https://cert-portal.siemens.com/productcert/html/ssa-127084.html (0b142b55-0307-4c5a-b3c9-f314f3fb7c5e)

## Provenance

- CNA: fortinet: https://www.cve.org/CVERecord?id=CVE-2026-71407; retrieved 2026-11-10; source updated 2026-11-10

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-71407; retrieved 2026-11-06; source updated 2026-11-06

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-71407; retrieved 2026-11-10; source updated Not reported

Revision: eb9f73d87705e3da1583929625ebf8c9d7b2118209eacab8772cee309c995995

Canonical: https://y2.dev/cve/CVE-2026-71407

## 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.