# CVE-2026-59837: Memory corruption in FortiOS

> Privileged authenticated attackers can execute arbitrary code via crafted HTTP requests due to a stack-based buffer overflow in Fortinet products.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Jul 2026
- **Updated:** 29 Oct 2026
- **Also known as:** GHSA-wxrh-6ch6-6hp4

## What is CVE-2026-59837?

CVE-2026-59837 is a medium-severity memory corruption vulnerability in Fortinet Fortios, published on 14 Jul 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

A stack-based buffer overflow vulnerability in Fortinet FortiOS 7.4.0 through 7.4.1, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4 all versions, FortiPAM 1.8.0 through 1.8.2, FortiPAM 1.7 all versions, FortiPAM 1.6 all versions, FortiPAM 1.5 all versions, FortiPAM 1.4 all versions, FortiPAM 1.3 all versions, FortiPAM 1.2 all versions, FortiPAM 1.1 all versions, FortiPAM 1.0 all versions, FortiProxy 7.4.0 through 7.4.13, FortiProxy 7.2 all versions may allow a privileged authenticated attacker who can bypass stack protection and ASLR to execute arbitrary code or commands via crafted HTTP requests.

Weakness: CWE-121 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2026-59837?

It affects 3 products.


Products: Fortinet Fortios, Fortinet Fortipam, Fortinet Fortiproxy.

## How do I fix CVE-2026-59837?

No fix has been published for CVE-2026-59837 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-59837 being exploited?

There is no known exploitation of CVE-2026-59837 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-2026-59837 and fix it if it is affected.

What it is: CVE-2026-59837 is a medium-severity memory corruption vulnerability in Fortinet Fortios, published on 14 Jul 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-59837 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-2026-59837/ (Markdown: https://insights.sbomify.com/CVE-2026-59837/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-59837
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-59837
- OSV: https://osv.dev/vulnerability/CVE-2026-59837

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-59837/
Summaries are generated and may contain mistakes; the official description above is the record.