Fortinet FortiWeb up to 7.4.11/7.6.6/8.0.3 out-of-bounds write

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.1$0-$5k0.00

Summaryinfo

A vulnerability was found in Fortinet FortiWeb up to 7.4.11/7.6.6/8.0.3. It has been rated as critical. This affects an unknown function. Performing a manipulation results in out-of-bounds write. This vulnerability is identified as CVE-2026-40688. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability classified as critical has been found in Fortinet FortiWeb up to 7.4.11/7.6.6/8.0.3. This affects an unknown function. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. CWE is classifying the issue as CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

A out-of-bounds write vulnerability in Fortinet FortiWeb 8.0.0 through 8.0.3, FortiWeb 7.6.0 through 7.6.6, FortiWeb 7.4.0 through 7.4.11 may allow attacker to execute unauthorized code or commands via

It is possible to read the advisory at fortiguard.fortinet.com. This vulnerability is uniquely identified as CVE-2026-40688 since 04/15/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. The exploitation needs additional levels of successful authentication. The technical details are unknown and an exploit is not publicly available.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-1122). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

  • Fortinet FortiWeb

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.2
VulDB Meta Temp Score: 7.1

VulDB Base Score: 7.2
VulDB Temp Score: 6.9
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.2
CNA Vector (fortinet): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Timelineinfo

04/15/2026 Advisory disclosed
04/15/2026 +0 days CVE reserved
04/15/2026 +0 days VulDB entry created
04/15/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: fortinet.com

Advisory: FG-IR-26-127
Status: Confirmed

CVE: CVE-2026-40688 (🔒)
GCVE (CVE): GCVE-0-2026-40688
GCVE (VulDB): GCVE-100-357651
CERT Bund: WID-SEC-2026-1122 - Fortinet FortiWeb: Schwachstelle ermöglicht Codeausführung

Entryinfo

Created: 04/15/2026 07:18
Updated: 04/15/2026 12:38
Changes: 04/15/2026 07:18 (64), 04/15/2026 12:38 (7)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion

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