Cyber Resilience

CVE-2026-39811

Medium

Published: 14 April 2026

Published
14 April 2026
Modified
21 April 2026
KEV Added
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Patch
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CVSS Score v3.1 4.9 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0014 33.8th percentile
Risk Priority 10 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-39811 is a medium-severity Integer Overflow or Wraparound (CWE-190) vulnerability in Fortinet Fortiweb. Its CVSS base score is 4.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 33.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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>

CWE(s)
CWE-190

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
attack.mitre.org →
Why these techniques?

Integer overflow in FortiWeb directly enables application exploitation to crash the service (T1499.004).

Confidence: MEDIUM · MITRE ATT&CK Enterprise v18.1

Affected Assets

fortinet
fortiweb
7.0.0 — 7.0.13 · 7.2.0 — 7.2.13 · 7.4.0 — 7.4.12

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References