9.8

CVE-2025-59718: Fortinet Multiple Products Improper Verification of Cryptographic Signature Vulnerability

CVSS: 9.8v3.1CriticalKEVAnalyzed
Published 09-12-2025Last modified 15-10-2026
Open JSON

Vulnerability summary

CVE-2025-59718 is a critical (CVSS 9.8) vulnerability in Fortinet Multiple Products. It is known to be exploited: CISA and ENISA list it, first on 16-12-2025. EPSS estimates a 68.29% chance of exploitation in the next 30 days, higher than 99.3% of scored vulnerabilities.

Overall risk
85/100
0100
Critical · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (NVD)
EPSS score
68.29%
0%100%
Critical · 0.00 pp in 30 days
KEVListedCISA · ENISA
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 09-12-2025
    PublishedVulnerability first disclosed.
  2. 16-12-2025
    Added to CISA KEVFortinet Multiple Products Improper Verification of Cryptographic Signature Vulnerability
  3. 23-12-2025
    CISA remediation dueApply mitigations per vendor instructions.
  4. 27-01-2026
    Added to ENISA KEVAdded to the ENISA known exploited vulnerabilities catalog.
  5. 15-10-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

68.29%

Chance of exploitation in the next 30 days

Percentile

99%

Versus all other CVEs

30-day change

0.00 pp

From 68.29% on 19-09-2026

19-09-202619-10-2026
EPSS score
68.29%

Known exploited

Compare KEV catalogs
CISA KEVListed
Added
16-12-2025
Federal due date
23-12-2025
ENISA CNWListed
Added
27-01-2026

CISA 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. fortiguard.fortinet.com/psirt/FG-IR-25-647 docs.fortinet.com/upgrade-tool/fortigate nvd.nist.gov/vuln/detail/CVE-2025-59718

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Fortinet3 products
  • fortios≥ 7.0.0, < 7.0.18 | ≥ 7.2.0, < 7.2.12 | ≥ 7.4.0, < 7.4.9 | ≥ 7.6.0, < 7.6.4 | ≥ 7.6.0, ≤ 7.6.3 | ≥ 7.4.0, ≤ 7.4.8 | ≥ 7.2.0, ≤ 7.2.11 | ≥ 7.0.0, ≤ 7.0.17
  • fortiproxy≥ 7.0.0, < 7.0.22 | ≥ 7.2.0, < 7.2.15 | ≥ 7.4.0, < 7.4.11 | ≥ 7.6.0, < 7.6.4 | ≥ 7.6.0, ≤ 7.6.3 | ≥ 7.4.0, ≤ 7.4.10 | ≥ 7.2.0, ≤ 7.2.14 | ≥ 7.0.0, ≤ 7.0.21
  • fortiswitchmanager≥ 7.0.0, < 7.0.6 | ≥ 7.2.0, < 7.2.7 | ≥ 7.2.0, ≤ 7.2.6 | ≥ 7.0.0, ≤ 7.0.5
Siemens1 product

2 vendors · 4 products

References

4 links