Is CVE-2026-126163 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-126163 being exploited in the wild.

How severe is CVE-2026-126163?

High severity, with a CVSS score of 8.1, published 11 November 2026.

Which products and versions are affected?

Fortinet FortiMail 8.0.0 through 8.0.1.

Is there a fix for CVE-2026-126163?

Yes: fixed in FortiMail 8.0.2 and above. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-126163 attacked?

It is attacked over the network, in a network appliance.

Am I affected by CVE-2026-126163?

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.

CVE-2026-126163: Fortinet FortiMail format string in SMTP

CVE-2026-126163 · Severity: high · CVSS 8.1 · Published 2026-11-11

FortiMail is an email security gateway that filters and protects corporate email. A format string vulnerability in its SMTP command processor allows a remote attacker without authentication to execute arbitrary code on the system, potentially leading to full system compromise and access to all email data.

Technologies: Fortinet FortiMail. Vendors: Fortinet.

Quick answers

Is CVE-2026-126163 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-126163 being exploited in the wild.
How severe is CVE-2026-126163?: High severity, with a CVSS score of 8.1, published 11 November 2026.
Which products and versions are affected?: Fortinet FortiMail 8.0.0 through 8.0.1.
Is there a fix for CVE-2026-126163?: Yes: fixed in FortiMail 8.0.2 and above. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-126163 attacked?: It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-126163?: 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 and above

Technical details

A use-after-free or format string vulnerability exists in the SMTP API component (CWE-134) of FortiMail 8.0.0 and 8.0.1. An unauthenticated remote attacker can trigger code execution by sending a specially crafted SMTP command that exploits improper handling of format string input. The attack requires no authentication or user interaction, making it highly exploitable.

Affected products

Fortinet FortiMail 8.0.0 through 8.0.1

Timeline

2026-11-10: disclosed
2026-10-05: patched: FortiMail Cloud updated to v7.6.7 GA or v8.0.2 GA

References

https://fortiguard.fortinet.com/psirt/FG-IR-26-215

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