Vulnerability

CVE-2026-40688

High· 7.2ZDICVSS7.2EPSS0%

.rules3/5

ZDI-26-266: Fortinet FortiWeb cat_cgi_paths Out-Of-Bounds Write Remote Code Execution Vulnerability

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Fortinet FortiWeb. Authentication is required to exploit this vulnerability. The ZDI has assigned a CVSS rating of 8.8. The following CVEs are assigned: CVE-2026-40688.

Threat signal

75/100

High

Severity

high

CVSS

7.2

EPSS

Active

CVSS

v3.1via NVDOpen in FIRST calculator →

7.2/ 10HIGHCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Attack VectorNetworkExploitable remotely over the internet — no local access needed.
Attack ComplexityLowNo special conditions — exploit works reliably.
Privileges RequiredHighAdmin / root privileges required.
User InteractionNoneFully automated — no victim action needed.
ScopeUnchangedImpact contained to the vulnerable component.
Confidentiality ImpactHighTotal disclosure of sensitive data.
Integrity ImpactHighTotal compromise of integrity — full data modification possible.
Availability ImpactHighTotal loss of availability — full DoS possible.

EPSS

Exploit prediction · 30-day horizonFIRST.org →

0.12%

probability of exploitation in next 30 days

p31

higher than 31% of all CVEs

3-day trend↑ 0pp

Low exploitation likelihood — defer if no other signals fire.

Vendor VEX

No VEX statements published for CVE-2026-40688. Vendors publish VEX (Vulnerability Exploitability eXchange) to assert per-product whether a CVE is actually exploitable in their distribution.

SSVCTrack

Total impact on non-trivial mission systems

exploitation: none
automatable: no
impact: total
mission: support

Lifecycle

2026-04-15Published
2026-04-15Last modified2 sources

References

http://www.zerodayinitiative.com/advisories/ZDI-26-266/

No source-event history recorded yet. New revisions will appear here as ingestors re-fetch this CVE.