Assessment
Why it matters
CISA lists this vulnerability as known to be exploited; exploitation is confirmed; EPSS is 63.4%; technical severity is CVSS 9.8.
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.
Who should care
- Teams operating FortiOS, Fortiproxy, Fortiswitchmanager +2 more
- Vulnerability and exposure management teams
- Security operations teams monitoring exploitation activity
Response plan
What I would do
- Confirm whether FortiOS, Fortiproxy, Fortiswitchmanager +2 more is present in the environment.
- Identify affected versions and establish whether vulnerable services are exposed or reachable.
- Fortinet Security advisory FG IR 25 647
- Review relevant security telemetry for evidence of attempted or successful exploitation.
- Document the remediation decision and track it to verified completion.
Treatment intelligence
Remediation intelligence
Vendor sources are listed before government and third-party guidance. Confirm product applicability and change prerequisites before deployment.
Technical details
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CWE
- CWE-347
- Affected versions
- Fortinet FortiOS (Start Including 7.0.0, End Excluding 7.0.18 | Start Including 7.2.0, End Excluding 7.2.12 | Start Including 7.4.0, End Excluding 7.4.9 | Start Including 7.6.0, End Excluding 7.6.4); Fortinet Fortiproxy (Start Including 7.0.0, End Excluding 7.0.22 | Start Including 7.2.0, End Excluding 7.2.15 | Start Including 7.4.0, End Excluding 7.4.11 | Start Including 7.6.0, End Excluding 7.6.4); Fortinet Fortiswitchmanager (Start Including 7.0.0, End Excluding 7.0.6 | Start Including 7.2.0, End Excluding 7.2.7); Fortinet Multiple Products; Siemens Ruggedcom Ape1808 Firmware (Version -)
- Fixed versions
- Fortinet FortiOS (Fixed from 7.0.18, 7.2.12, 7.4.9, 7.6.4); Fortinet Fortiproxy (Fixed from 7.0.22, 7.2.15, 7.4.11, 7.6.4); Fortinet Fortiswitchmanager (Fixed from 7.0.6, 7.2.7)
- Published
- 9 December 2025
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
Signal timeline
- CVE published
- Added to CISA KEV
- Latest EPSS score: 63.4%
- Signal calculated at 81