# CVE-2025-59718: Fortinet Multiple Products Improper Verification of Cryptographic Signature

> An unauthenticated attacker can bypass FortiCloud SSO login authentication by sending a crafted SAML response, gaining unauthorized access to Fortinet devices.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C`)
- **Exploited in the wild:** Yes, since 16 Dec 2025 (CISA KEV)
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Dec 2025
- **Updated:** 15 Oct 2026
- **Also known as:** GHSA-fjj2-p33c-f8qq

## What is CVE-2025-59718?

CVE-2025-59718 is a critical authentication bypass vulnerability in Fortinet Fortios, published on 9 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A improper verification of cryptographic signature vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2.0 through 7.2.11, FortiOS 7.0.0 through 7.0.17, FortiProxy 7.6.0 through 7.6.3, FortiProxy 7.4.0 through 7.4.10, FortiProxy 7.2.0 through 7.2.14, FortiProxy 7.0.0 through 7.0.21, FortiSwitchManager 7.2.0 through 7.2.6, FortiSwitchManager 7.0.0 through 7.0.5 allows an unauthenticated attacker to bypass the FortiCloud SSO login authentication via a crafted SAML response message.

Weakness: CWE-347 (Improper Verification of Cryptographic Signature)

## Which versions are affected by CVE-2025-59718?

It affects 4 products.


Products: Fortinet Fortios, Fortinet Fortiproxy, Fortinet Fortiswitchmanager, Siemens Ruggedcom Ape1808 Firmware.

## How do I fix CVE-2025-59718?

No fix has been published for CVE-2025-59718 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 23 Dec 2025.

## Is CVE-2025-59718 being exploited?

Yes. Attackers have exploited CVE-2025-59718 in the wild since at least 16 Dec 2025.

Public exploit code:

- Fortinet announced two closely related authentication‑bypass vulnerabilities on 9 December 2025. Both flaws involve improper verification of cryptographic signatures (CWE‑347) in the handling of SAML responses for the FortiCloud SSO login feature. (github_poc): https://github.com/exfil0/CVE-2025-59718-PoC
- PoC para determinar si Fortinet es vulnerable a CVE-2025-59718 / CVE-2025-59719 (github_poc): https://github.com/moften/CVE-2025-59718-Fortinet-Poc

## Other vulnerabilities in Fortinet Fortios

- [CVE-2024-23113](https://insights.sbomify.com/CVE-2024-23113/): Fortinet Multiple Products Format String (critical 9.8, exploited in the wild)
- [CVE-2022-40684](https://insights.sbomify.com/CVE-2022-40684/): Fortinet Multiple Products Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2024-55591](https://insights.sbomify.com/CVE-2024-55591/): Fortinet FortiOS and FortiProxy Authentication Bypass (critical 9.6, exploited in the wild)
- [CVE-2024-21762](https://insights.sbomify.com/CVE-2024-21762/): Fortinet FortiOS Out-of-Bound Write (critical 9.6, exploited in the wild)
- [CVE-2022-42475](https://insights.sbomify.com/CVE-2022-42475/): Fortinet FortiOS Heap-Based Buffer Overflow (critical 9.3, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-59718 and fix it if it is affected.

What it is: CVE-2025-59718 is a critical authentication bypass vulnerability in Fortinet Fortios, published on 9 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2025-59718 in the wild since at least 16 Dec 2025.

Affected product: Fortinet Fortios. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-59718/ (Markdown: https://insights.sbomify.com/CVE-2025-59718/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-59718
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-59718
- OSV: https://osv.dev/vulnerability/CVE-2025-59718

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-59718/
Summaries are generated and may contain mistakes; the official description above is the record.