CVE-2025-59718
Fortinet Multiple Products: Improper Verification of Cryptographic Signature
As of , CVE-2025-59718 in Fortinet Multiple Products is on CISA's list of exploited vulnerabilities: CISA listed it on . Our patch-first group: Patch this week.
- Exploited
- Yes: CISA listed it on 16 December 2025
- US federal deadline
- 23 December 20257 days after CISA listed it. US federal civilian agencies must fix it by then.
- Used in ransomware campaigns
- Not known to CISA
- EPSS score
- 0.68Higher than 99% of the CVEs EPSS scores. EPSS estimates the chance of exploitation activity in the next 30 days.
- Public exploit
- None foundNeither Metasploit nor Exploit-DB lists one.
- Fix
- Vendor advice: docs.fortinet.com and fortiguard.fortinet.comLinks below, from CISA's entry.
What CISA says to do
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
CISA's required action
What the flaw is
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 description
A improper verification of cryptographic signature vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2.0 through 7.2.11, FortiOS 7.0.0 through 7.0.17, FortiProxy 7.6.0 through 7.6.3, FortiProxy 7.4.0 through 7.4.10, FortiProxy 7.2.0 through 7.2.14, FortiProxy 7.0.0 through 7.0.21, FortiSwitchManager 7.2.0 through 7.2.6, FortiSwitchManager 7.0.0 through 7.0.5 allows an unauthenticated attacker to bypass the FortiCloud SSO login authentication via a crafted SAML response message.
The CVE record's description, from fortinet
- CVE published
- 9 December 2025
- Assigned by
- fortinet
- CVSS
- 9.1 Critical (CVSS 3.1, from the CNA)
- CWE-347
- Improper Verification of Cryptographic Signature
- CISA SSVC, exploitation
- active
- CISA SSVC, automatable
- yes
- CISA SSVC, technical impact
- total
Timeline
- The CVE record was published.
- CISA added it to its list of exploited vulnerabilities.
- The US federal deadline to fix it.
Multiple Products: other exploited entries
| Vulnerability | Product | Our group | Listed | Deadline | EPSS |
|---|---|---|---|---|---|
| CVE-2025-25249Heap-based Buffer Overflow | Fortinet Multiple Products | Patch nowForensic triage required by CISA | 0.04 | ||
| CVE-2022-40684Authentication Bypass | Fortinet Multiple Products | Patch this weekRansomware use; Metasploit module; EPSS 0.99 | 0.99 | ||
| CVE-2026-24858Authentication Bypass Using an Alternate Path or Channel | Fortinet Multiple Products | Patch this weekEPSS 0.86 | 0.86 | ||
| CVE-2024-23113Format String | Fortinet Multiple Products | Patch this weekEPSS 0.62 | 0.62 | ||
| CVE-2025-32756Stack-Based Buffer Overflow | Fortinet Multiple Products | Patch soon | 0.30 |
Read further
- CVE recordcve.org
- NVD entrynvd.nist.gov
- CISA's catalogcisa.gov
- EPSS for this CVEapi.first.org