# CVE-2026-126259: Auth bypass in FortiOS

> Unauthenticated attackers can send crafted HA packets to run commands as super admin on FortiOS with specific HA configurations.

- **Severity:** Critical 9.0 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Harmful if only installed:** No
- **Needs a specific call:** No
- **Fix available:** No
- **Published:** 11 Nov 2026
- **Updated:** 12 Nov 2026
- **Also known as:** GHSA-f2f6-qwmc-g833

## What is CVE-2026-126259?

CVE-2026-126259 is a critical authentication bypass vulnerability in Fortinet FortiOS, published on 11 Nov 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A missing authentication for critical function vulnerability in Fortinet FortiOS 8.0.0, FortiOS 7.6.0 through 7.6.7, FortiOS 7.4.0 through 7.4.12, FortiOS 7.2.0 through 7.2.13 may allow an unauthenticated attacker with HA FGSP + standalone-config-sync, or autoscale to execute command as super admin via crafted HA packets.

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2026-126259?

Only installations with a non-default setting turned on are exposed.


## How do I fix CVE-2026-126259?

No fix has been published for CVE-2026-126259 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-126259 being exploited?

There is no known exploitation of CVE-2026-126259 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-126259 and fix it if it is affected.

What it is: CVE-2026-126259 is a critical authentication bypass vulnerability in Fortinet FortiOS, published on 11 Nov 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-2026-126259 in the wild and no public exploit code.
Exposure: Only installations with a non-default setting turned on are exposed.

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-2026-126259/ (Markdown: https://insights.sbomify.com/CVE-2026-126259/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-126259
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-126259
- OSV: https://osv.dev/vulnerability/CVE-2026-126259

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-126259/
Summaries are generated and may contain mistakes; the official description above is the record.