Threat Intelligence / CVE / CVE-2025-59719

CVE-2025-59719 — Fortinet Fortiweb

CVSS v3.1 9.8 (CRITICAL) · EPSS 0.1% (higher than 36.9% of all scored CVEs) · Priority 6.4/10 · Published 2025-12-09

As of 2025-12-09, CVE-2025-59719 is a CRITICAL-severity vulnerability in Fortinet Fortiweb, CVSS v3.1 9.8, EPSS 0.1% (36.9th percentile). Threadlinqs Intelligence links 2 tracked threat campaigns to CVE-2025-59719, most recently “FortiBleed: Mass Credential Compromise Campaign Against Internet-Exposed Fortinet FortiGate Devices (86,644 Devices, 194 Countries)”.

Last updated: 2025-12-09

What is CVE-2025-59719?

An improper verification of cryptographic signature vulnerability in Fortinet FortiWeb 8.0.0, FortiWeb 7.6.0 through 7.6.4, FortiWeb 7.4.0 through 7.4.9 may allow an unauthenticated attacker to bypass the FortiCloud SSO login authentication via a crafted SAML response message.

The record classifies CVE-2025-59719 under weakness class CWE-347. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 2 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 277 days ago.

Severity and exploitation probability

CVSS v3.1 base score: 9.8 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (FIRST): 0.1% probability of exploitation in the next 30 days, higher than 36.9% of all scored CVEs
CISA KEV: Not listed in the CISA Known Exploited Vulnerabilities catalog
Threadlinqs priority: 6.4/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
Published: 2025-12-09

Is CVE-2025-59719 being exploited?

It currently carries a trending score of 14 in the Threadlinqs vulnerability feed.

Affected products and versions

Fortinet: Fortiweb, Fortiweb 8.0.0

How to fix CVE-2025-59719

The record marks a vendor fix as available for CVE-2025-59719. Patch reference: https://fortiguard.fortinet.com/psirt/FG-IR-24-535. Vendor advisory: https://fortiguard.fortinet.com/psirt/FG-IR-25-647. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

Threat activity tracking CVE-2025-59719

2 tracked threats in the Threadlinqs corpus reference CVE-2025-59719, either in the campaign’s CVE list or as an indicator on the campaign record.

FortiBleed: Mass Credential Compromise Campaign Against Internet-Exposed Fortinet FortiGate Devices (86,644 Devices, 194 Countries) — CRITICAL · 2026-07-11
FortiGate SSO Authentication Bypass Campaign (CVE-2025-59718, CVE-2025-59719, CVE-2026-24858) — CRITICAL · 2026-03-10

Sources

Seeded from research and not yet processed by the Threadlinqs enrichment pipeline, so blank CVSS, EPSS or KEV fields above mean NOT MEASURED rather than measured-absent.

fortiguard.fortinet.com

Full detection coverage & IOCs for threats exploiting CVE-2025-59719 are available via the Threadlinqs MCP server (Purple tier). View plans →

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