CVE-2026-40688

An out-of-bounds write vulnerability [CWE-787] 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 a remote privileged attacker to execute arbitrary code or command via crafted HTTP requests.

Published: 2026-04-14 Last update: 2026-04-20 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-40688 is rated Moderate Risk (40.3/100): CVSS High severity, with low exploitation likelihood (EPSS 0.14%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-40688

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-22 0.18% 0.14% -0.04%
2 2026-04-21 0.56% 0.18% -0.39%
3 2026-04-20 — 0.56% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-40688

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.2 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.2 5.9 [email protected]

Weakness enumeration for CVE-2026-40688

Affected software / configurations for CVE-2026-40688

Vendor Product Version Raw CPE
fortinet fortiweb >= 7.4.0, < 7.4.12 cpe:2.3:a:fortinet:fortiweb:*:*:*:*:*:*:*:*
fortinet fortiweb >= 7.6.0, < 7.6.7 cpe:2.3:a:fortinet:fortiweb:*:*:*:*:*:*:*:*
fortinet fortiweb >= 8.0.0, < 8.0.4 cpe:2.3:a:fortinet:fortiweb:*:*:*:*:*:*:*:*

References for CVE-2026-40688

cvelogic Threat Intelligence