# CVE-2026-126148: Fortinet FortiMail OS command injection in HA join-request

Source: https://junglewise.ai/threats/cve-2026-126148-a-improper-neutralization-of-special-elements-used-in-an-os  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-11. Updated: 2026-11-11  
License: CC BY 4.0 with a link back

CVE-2026-126148 · Severity: critical · CVSS 9.8 · Published 2026-11-11

FortiMail is an email security gateway that protects organizations from malicious emails and threats. An unauthenticated attacker can inject arbitrary operating system commands via specially crafted HA (high-availability) cluster join requests, allowing them to execute code with system privileges and gain complete control of the mail server. This vulnerability requires no authentication or user interaction, making it immediately exploitable from the network.

Technologies: [Fortinet FortiMail](https://junglewise.ai/threats/technologies/fortimail). Vendors: [Fortinet](https://junglewise.ai/threats/vendors/fortinet).

## Quick answers

**Is CVE-2026-126148 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-126148 being exploited in the wild.

**How severe is CVE-2026-126148?** Critical severity, with a CVSS score of 9.8, published 11 November 2026.

**Which products and versions are affected?** Fortinet FortiMail 8.0.0 through 8.0.1, 7.6.0 through 7.6.6.

**Is there a fix for CVE-2026-126148?** Yes: fixed in FortiMail 8.0.2 or above; FortiMail 7.6.7 or above. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-126148 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-126148?** Check whether you run Fortinet FortiMail at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in FortiMail 8.0.2 or above; FortiMail 7.6.7 or above

## Technical details

An improper neutralization of special elements in OS commands (CWE-77) exists in FortiMail's CLI component when processing HA join-request packets. An unauthenticated network attacker can craft malicious HA join-request packets containing shell metacharacters to inject arbitrary OS commands that execute with elevated privileges. The vulnerability affects FortiMail 8.0.0–8.0.1 and 7.6.0–7.6.6; patches are available.

## Affected products

- Fortinet FortiMail 8.0.0 through 8.0.1, 7.6.0 through 7.6.6

## Timeline

- 2026-10-05: other: Fortinet remediated this issue in FortiMail Cloud
- 2026-11-10: disclosed: Initial publication

## References

- [https://fortiguard.fortinet.com/psirt/FG-IR-26-200](https://fortiguard.fortinet.com/psirt/FG-IR-26-200)

## Related threats

- [Fortinet FortiMail SQL injection](https://junglewise.ai/threats/cve-2026-126263-a-improper-neutralization-of-special-elements-used-in-an-sql)
- [Fortinet FortiMail argument injection in administrative interface](https://junglewise.ai/threats/cve-2026-126169-a-improper-neutralization-of-argument-delimiters-in-a-command)
- [Fortinet FortiMail argument injection in administrative interface](https://junglewise.ai/threats/cve-2026-126168-a-improper-neutralization-of-argument-delimiters-in-a-command)
- [Fortinet FortiMail command injection in admin GUI](https://junglewise.ai/threats/cve-2026-126167-a-improper-neutralization-of-special-elements-used-in-a-command)
- [Fortinet FortiMail argument injection in admin interface](https://junglewise.ai/threats/cve-2026-126166-a-improper-neutralization-of-argument-delimiters-in-a-command)