CVE-2026-126159: Fortinet FortiMail authorization bypass in quarantine API

CVE-2026-126159 · Severity: high · CVSS 7.5 · Published 2026-11-11

FortiMail is a secure email gateway that filters and quarantines dangerous messages. An unauthenticated attacker can bypass authorization checks to release or permanently delete quarantined emails from any mailbox by sending a crafted request to the quarantine API. This allows attackers to suppress security alerts, recover deleted phishing messages, or cause email loss without authentication.

Technologies: Fortinet FortiMail. Vendors: Fortinet.

Quick answers

Is CVE-2026-126159 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-126159 being exploited in the wild.
How severe is CVE-2026-126159?
High severity, with a CVSS score of 7.5, 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, 7.4.0 through 7.4.8, 7.2 all versions.
Is there a fix for CVE-2026-126159?
Yes: fixed in FortiMail 8.0.2 or above, 7.6.7 or above, 7.4.9 or above; 7.2 requires migration to a fixed release. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-126159 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-126159?
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, 7.6.7 or above, 7.4.9 or above; 7.2 requires migration to a fixed release

Technical details

An authorization bypass through user-controlled key vulnerability in FortiMail's quarantine release API allows unauthenticated attackers to release or delete quarantined messages for arbitrary mailboxes. The flaw stems from improper access control in the API endpoint that processes quarantine release requests, where authorization is based on user-controllable parameters rather than server-side validation. An attacker can directly craft requests to manipulate or remove quarantined content without authentication.

Affected products

  • Fortinet FortiMail 8.0.0 through 8.0.1, 7.6.0 through 7.6.6, 7.4.0 through 7.4.8, 7.2 all versions

Timeline

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

References

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