Exploited vulnerabilities / CVE-2025-59718
Confirmed exploited · exploited vulnerability · Fortinet Multiple ProductsCVE-2025-59718
Fortinet Multiple Products exploited vulnerability, confirmed exploited in the wild.
Fortinet FortiOS, FortiSwitchMaster, FortiProxy, and FortiWeb contain an improper verification of cryptographic signature vulnerability that may allow an unauthenticated attacker to bypass the FortiCloud SSO login authentication via a crafted SAML message. Please be aware that CVE-2025-59719 pertains to the same problem and is mentioned in the same vendor advisory. Ensure to apply all patches mentioned in the advisory.
| CISA's name for it | Fortinet Multiple Products Improper Verification of Cryptographic Signature Vulnerability |
|---|---|
| Vendor and product | Fortinet · Multiple Products |
| Type | exploited vulnerability · CWE-347 |
| Exploited | Confirmed by CISA listed 16 December 2025 |
| Likelihood | one of the most likely to be exploited of every vulnerability tracked |
| Deadline | 23 December 2025 · already passed |
| Used in ransomware | Not reported |
| Advisories | fortiguard.fortinet.com ↗ · docs.fortinet.com ↗ · nvd.nist.gov ↗ |
Three steps, in this order
Apply the vendor's fix or mitigation; CISA lists only vulnerabilities seen exploited.
If you cannot patch now, restrict network access to the affected product.
Check for signs of compromise since the date it was added to the list.
| CISA's required action | Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. |
|---|
Know before someone else finds it
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CVE-2025-59718 in short
Is CVE-2025-59718 being exploited?
Yes. CISA added CVE-2025-59718 to its Known Exploited Vulnerabilities catalogue on 16 December 2025, which it does only on evidence of exploitation in the wild.
What is the CISA deadline for CVE-2025-59718?
US federal agencies must remediate it by 23 December 2025. Everyone else should treat that date as the latest safe point to patch an internet-facing system.
How likely is CVE-2025-59718 to be exploited in the next 30 days?
FIRST's Exploit Prediction Scoring System gives it 68%, the 99th percentile of every CVE it scores.
How do I fix CVE-2025-59718?
Apply the vendor's fix or mitigation; CISA lists only vulnerabilities seen exploited. If you cannot patch now, restrict network access to the affected product. Check for signs of compromise since the date it was added to the list.
Other Fortinet vulnerabilities being exploited
| CVE | Product | Type | Listed |
|---|---|---|---|
| CVE-2025-61624 | Multiple Products | path traversal | 16 October 2026 |
| CVE-2026-104286 | FortiMail | path traversal | 1 October 2026 |
| CVE-2025-25249 | Multiple Products | memory corruption | 9 September 2026 |
| CVE-2025-68686 | FortiOS | exploited vulnerability | 27 July 2026 |
| CVE-2026-25089 | FortiSandbox | command injection | 16 July 2026 |
| CVE-2026-39808 | FortiSandbox | command injection | 16 July 2026 |
Sources: CISA Known Exploited Vulnerabilities catalogue (released 10 November 2026) and FIRST EPSS. Page compiled automatically by SAK T.L.M, the threat-intelligence tool of SAK T.E.C, on 13 November 2026.