Integer Overflow in Fortinet FortiWeb Causes Denial of Service

Publication date: 2026-04-14

Last updated on: 2026-04-21

Assigner: Fortinet, Inc.

Description

A integer overflow or wraparound vulnerability in Fortinet FortiWeb 8.0.0 through 8.0.3, FortiWeb 7.6.0 through 7.6.6, FortiWeb 7.4 all versions, FortiWeb 7.2 all versions, FortiWeb 7.0 all versions may allow attacker to denial of service via <insert attack vector here>

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-04-14

Last Modified

2026-04-21

Generated

2026-07-06

AI Q&A

2026-04-14

EPSS Evaluated

2026-07-05

NVD

CVE-2026-39811

EUVD

EUVD-2026-22340

Affected Vendors & Products

Vendor	Product	Version / Range
fortinet	fortiweb	From 7.6.0 (inc) to 7.6.7 (exc)
fortinet	fortiweb	From 8.0.0 (inc) to 8.0.4 (exc)
fortinet	fortiweb	From 7.0.0 (inc) to 7.0.13 (inc)
fortinet	fortiweb	From 7.2.0 (inc) to 7.2.13 (inc)
fortinet	fortiweb	From 7.4.0 (inc) to 7.4.12 (inc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-190	The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

Attack-Flow Graph

Executive Summary

This vulnerability is an integer overflow or wraparound issue found in multiple versions of Fortinet FortiWeb (versions 7.0 all versions through 8.0.3). An attacker may exploit this flaw to cause a denial of service (DoS) condition.

Impact Analysis

The primary impact of this vulnerability is that an attacker could cause a denial of service, potentially disrupting the availability of the affected FortiWeb systems.

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