CVE-2026-59840

A buffer over-read vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4 all versions, FortiProxy 7.6.0 th

Severity
Medium 4.1
CVSS 3.1
Exploited
Not listed
EPSS
0.003
24.4th percentile
Discovered by
Third party
Vendor advisory field
Published
Jul 14, 2026
Assigned by fortinet

Description

A buffer over-read vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4 all versions, FortiProxy 7.6.0 through 7.6.5, FortiProxy 7.4.0 through 7.4.13, FortiProxy 7.2 all versions, FortiProxy 7.0 all versions may allow attacker to information disclosure via <insert attack vector here>

Weakness: CWE-126

Affected products

Vendor Product Category Matched by
Fortinet FortiOS Firewall / NGFW cna-assigner
Fortinet FortiPAM Identity / IAM / MFA cna-assigner
Fortinet FortiProxy SASE / SSE / Secure Web cna-assigner
Fortinet FortiSwitch Routing & Switching cna-assigner
Vendor-reported products (5)
  • Fortinet · FortiOS
  • Fortinet · FortiPAM
  • Fortinet · FortiSwitchManager
  • Fortinet · FortiProxy
  • Siemens · RUGGEDCOM APE1808

Credit

Fortinet is pleased to thank Vang3lis and Cyth from VARAS@IIE for reporting this vulnerability under responsible disclosure.

Vendor remediation

Upgrade to FortiOS version 7.6.4 or above Upgrade to FortiOS version 7.4.9 or above Fortinet remediated this issue in FortiSASE version 25.4.b and hence customers do not need to perform any action. Upgrade to FortiProxy version 7.6.6 or above Upgrade to FortiProxy version 7.4.14 or above

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