Fortinet FortiClientWindows up to 7.2.11/7.4.3 buffer overflow

Summaryinfo

A vulnerability described as very critical has been identified in Fortinet FortiClientWindows up to 7.2.11/7.4.3. The affected element is an unknown function. Such manipulation leads to buffer overflow. This vulnerability is listed as CVE-2026-70465. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability was found in Fortinet FortiClientWindows up to 7.2.11/7.4.3. It has been rated as very critical. Affected by this issue is an unknown code block. The manipulation with an unknown input leads to a buffer overflow vulnerability. Using CWE to declare the problem leads to CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. Impacted is confidentiality, integrity, and availability. CVE summarizes:

A buffer copy without checking size of input ('classic buffer overflow') vulnerability in Fortinet FortiClientWindows 7.4.0 through 7.4.3, FortiClientWindows 7.2.0 through 7.2.11 may allow an unauthenticated attacker in a position to alter or craft DNS responses to the targeted host to execute arbitrary code via malicious packets.

The advisory is shared for download at fortiguard.fortinet.com. This vulnerability is handled as CVE-2026-70465 since 08/04/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 08/12/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• Fortinet

Name

• FortiClientWindows

Version

• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.2.5
• 7.2.6
• 7.2.7
• 7.2.8
• 7.2.9
• 7.2.10
• 7.2.11
• 7.4.0
• 7.4.1
• 7.4.2
• 7.4.3

License

• commercial

Website

• Vendor: https://www.fortinet.com/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Once again VulDB remains the best source for vulnerability data.

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