CVE-2025-59718: Fortinet Multiple Products Improper Verification of Cryptographic Signature Vulnerability
- Is it exploited?
Yes. CISA added it to the Known Exploited Vulnerabilities catalog on 16 Dec 2025, 7 days after the CVE record was published.
- How likely is exploitation in the next 30 days?
- 68.3%
EPSS score, percentile 99.3 of all scored records
- How severe?
- 9.1 Critical
CVSS v3.1 base score, given by the CNA
- What should I do?
CISA deadline 23 Dec 2025. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Affected
- 7.2.0 through 7.2.6
- 7.0.0 through 7.0.5
- 7.6.0 through 7.6.3
- 7.4.0 through 7.4.8
- 7.2.0 through 7.2.11
- 7.0.0 through 7.0.17
and 4 more in the table below
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
What to do
Required action, set by CISA
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 due date for this action: 23 December 2025.
Solution (from the CVE record)
Upgrade to FortiSwitchManager version 7.2.7 or above Upgrade to FortiSwitchManager version 7.0.6 or above Upgrade to FortiProxy version 7.6.4 or above Upgrade to FortiProxy version 7.4.11 or above Upgrade to FortiProxy version 7.2.15 or above Upgrade to FortiProxy version 7.0.22 or above Upgrade to FortiOS version 7.6.4 or above Upgrade to FortiOS version 7.4.9 or above Upgrade to FortiOS version 7.2.12 or above Upgrade to FortiOS version 7.0.18 or above Upgrade to FortiWeb version 8.0.1 or above Upgrade to FortiWeb version 7.6.5 or above Upgrade to FortiWeb version 7.4.10 or above Fortinet remediated this issue in FortiSASE version 25.3.b and hence customers do not need to perform any action. Upgrade to FortiPAM version 1.8.0 or above
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
Linked from CISA's catalog entry
- https://fortiguard.fortinet.com/psirt/FG-IR-25-647
- https://docs.fortinet.com/upgrade-tool/fortigate
- https://nvd.nist.gov/vuln/detail/CVE-2025-59718
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | 7.2.0 through 7.2.6 |
| Affected | 7.0.0 through 7.0.5 |
Versions not listed are: unaffected.
| Status | Versions |
|---|---|
| Affected | 7.6.0 through 7.6.3 |
| Affected | 7.4.0 through 7.4.8 |
| Affected | 7.2.0 through 7.2.11 |
| Affected | 7.0.0 through 7.0.17 |
Versions not listed are: unaffected.
| Status | Versions |
|---|---|
| Affected | 7.6.0 through 7.6.3 |
| Affected | 7.4.0 through 7.4.10 |
| Affected | 7.2.0 through 7.2.14 |
| Affected | 7.0.0 through 7.0.21 |
Versions not listed are: unaffected.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
About this vulnerability
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.
Summary: CISA's KEV catalog, as of 28 Oct 2026.
- CISA added CVE-2025-59718 to its Known Exploited Vulnerabilities (KEV) catalog on 16 Dec 2025.
- CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
- The due date CISA sets for the required action is 23 Dec 2025.
- The CVE record was published on 9 Dec 2025, 7 days before it was added to KEV.
- The CVE record carries a CVSS v3.1 base score of 9.1 (Critical), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 68.3% (percentile 99.3), as of 28 Oct 2026.
- CISA's SSVC assessment in the CVE record: exploitation active, automatable yes, technical impact total.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026. About the data.
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.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
Weakness
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.
Timeline
| Date | Event |
|---|---|
| 9 Dec 2025 | CVE record published |
| 16 Dec 2025 | Added to CISA KEV |
| 23 Dec 2025 | CISA due date for the required action |
| 15 Oct 2026 | CVE record last updated |
References
More exploited Fortinet vulnerabilities
- CVE-2025-61624: Fortinet Multiple Products Path Traversal Vulnerability
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- CVE-2025-25249: Fortinet Multiple Products Heap-based Buffer Overflow Vulnerability
- CVE-2025-68686: Fortinet FortiOS Exposure of Sensitive Information to an Unauthorized Actor Vulnerability
- CVE-2026-25089: Fortinet FortiSandbox OS Command Injection Vulnerability
- CVE-2026-39808: Fortinet FortiSandbox OS Command Injection Vulnerability