# CVE-2025-25253: Security feature bypass in FortiOS

> An unauthenticated attacker in a man-in-the-middle position can intercept and tamper with ZTNA proxy connections due to improper certificate host validation.

- **Severity:** Medium 6.8 (`CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Oct 2025
- **Updated:** 15 Oct 2026
- **Also known as:** GHSA-9gmg-hfch-x94j

## What is CVE-2025-25253?

CVE-2025-25253 is a medium-severity vulnerability in Fortinet Fortios, published on 14 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An Improper Validation of Certificate with Host Mismatch vulnerability [CWE-297] in FortiProxy version 7.6.1 and below, version 7.4.8 and below, 7.2 all versions, 7.0 all versions and FortiOS version 7.6.2 and below, version 7.4.8 and below, 7.2 all versions, 7.0 all versions ZTNA proxy may allow an unauthenticated attacker in a man-in-the middle position to intercept and tamper with connections to the ZTNA proxy

Weakness: CWE-297 (Improper Validation of Certificate with Host Mismatch)

## Which versions are affected by CVE-2025-25253?

It affects 2 products.


Products: Fortinet Fortios, Fortinet Fortiproxy.

## How do I fix CVE-2025-25253?

No fix has been published for CVE-2025-25253 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-25253 being exploited?

There is no known exploitation of CVE-2025-25253 in the wild and no public exploit code.

## 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-2025-25253 and fix it if it is affected.

What it is: CVE-2025-25253 is a medium-severity vulnerability in Fortinet Fortios, published on 14 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-25253 in the wild and no public exploit code.

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-2025-25253/ (Markdown: https://insights.sbomify.com/CVE-2025-25253/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-25253
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-25253
- OSV: https://osv.dev/vulnerability/CVE-2025-25253

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-25253/
Summaries are generated and may contain mistakes; the official description above is the record.