Vulnerability
ZDI-26-265: Fortinet FortiWeb cgi_buf_alloc Integer Overflow Denial-of-Service Vulnerability
This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of Fortinet FortiWeb. Authentication is required to exploit this vulnerability. The ZDI has assigned a CVSS rating of 6.5. The following CVEs are assigned: CVE-2026-39811.
No CVSS base score from NVD or GHSA yet. NVD typically scores within 24–72 hours of publication; GHSA usually within a day for OSS-flagged CVEs. Last record update .
For interim severity, fall back on KEV / EXPLOIT signals and the EPSS percentile (lower panel). Re-check this CVE after one cron tick — the score lands automatically when the source publishes.
Low exploitation likelihood — defer if no other signals fire.
No VEX statements published for CVE-2026-39811. Vendors publish VEX (Vulnerability Exploitability eXchange) to assert per-product whether a CVE is actually exploitable in their distribution.
No exploitation, limited impact or prevalence