CISA KEV catalog
Confirmed active exploitation.
Listed in CISA's catalog of Known Exploited Vulnerabilities: attackers are using it in real attacks. Patch it with priority.
- Name
- Fortinet FortiOS and FortiProxy Out-of-bounds Write
- Added to catalog
- Remediation due date (US federal)
- Required action
- Apply updates per vendor instructions.
Description
A heap buffer overflow in Fortinet FortiOS 6.0.0 through 6.0.4, 5.6.0 through 5.6.10, 5.4.0 through 5.4.12, 5.2.14 and earlier and FortiProxy 2.0.0, 1.2.8 and earlier in the SSL VPN web portal may cause the SSL VPN web service termination for logged in users due to a failure to properly handle javascript href data when proxying webpages.
Affected products
fortinet: fortiproxy; fortinet: fortios
References5
- fortiguard.com/advisory/FG-IR-18-388 MitigationVendor Advisory
- fortiguard.com/advisory/FG-IR-20-229 Vendor Advisory
- fortiguard.com/advisory/FG-IR-18-388 MitigationVendor Advisory
- fortiguard.com/advisory/FG-IR-20-229 Vendor Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=… US Government Resource
Metrics
- CVSS 3.1
-
6.5
MEDIUM
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 31% percentile: 98 · as of 10 November 2026
- CWE
- CWE-787
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