# CVE-2026-70465: Memory corruption in FortiClientWindows

> An unauthenticated attacker can execute arbitrary code on FortiClient Windows by sending malicious DNS responses, requiring immediate patching.

- **Severity:** High 7.3 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 Aug 2026
- **Updated:** 20 Oct 2026
- **Also known as:** GHSA-95wv-6wmf-f8vm

## What is CVE-2026-70465?

CVE-2026-70465 is a high-severity memory corruption vulnerability in Fortinet Forticlient, published on 12 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A buffer copy without checking size of input ('classic buffer overflow') vulnerability in Fortinet FortiClientWindows 7.4.0 through 7.4.3, FortiClientWindows 7.2.0 through 7.2.11 may allow an unauthenticated attacker in a position to alter or craft DNS responses to the targeted host to execute arbitrary code via malicious packets.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input)

## Which versions are affected by CVE-2026-70465?

It affects 1 product.


Products: Fortinet Forticlient.

## How do I fix CVE-2026-70465?

No fix has been published for CVE-2026-70465 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-70465 being exploited?

There is no known exploitation of CVE-2026-70465 in the wild and no public exploit code.

## Other vulnerabilities in Fortinet Forticlient

- [CVE-2019-17658](https://insights.sbomify.com/CVE-2019-17658/): Privilege escalation in Fortinet FortiClientWindows (critical 9.8)
- [CVE-2023-45590](https://insights.sbomify.com/CVE-2023-45590/): Code injection in FortiClientLinux (critical 9.4)
- [CVE-2017-14184](https://insights.sbomify.com/CVE-2017-14184/): Information disclosure in FortiClient SSLVPN Client for Linux (high 8.8)
- [CVE-2016-8493](https://insights.sbomify.com/CVE-2016-8493/): Privilege escalation in Fortinet FortiClient (high 8.8)
- [CVE-2020-15934](https://insights.sbomify.com/CVE-2020-15934/): Privilege escalation in FortiClientLinux (high 8.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-70465 and fix it if it is affected.

What it is: CVE-2026-70465 is a high-severity memory corruption vulnerability in Fortinet Forticlient, published on 12 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-70465 in the wild and no public exploit code.

Affected product: Fortinet Forticlient. 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-2026-70465/ (Markdown: https://insights.sbomify.com/CVE-2026-70465/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-70465
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-70465
- OSV: https://osv.dev/vulnerability/CVE-2026-70465

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-70465/
Summaries are generated and may contain mistakes; the official description above is the record.