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, Forti
Affects FortiOS, FortiProxy and FortiSwitchManager devices with FortiCloud SSO login enabled, which is off in default settings. The advisory says to upgrade to 7.6.4 or above.
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Listed in CISA KEV
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Actively exploited
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: active
- Automatable: yes
- Technical impact: total
Summary
Fortinet FortiOS, FortiProxy, and FortiSwitchManager are affected. An unauthenticated attacker could bypass FortiCloud single sign-on login authentication by sending a specially crafted SAML response, potentially gaining unauthorized access to the device.
Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.
Read the original 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.
Timeline
- CVE published
- Added to CISA KEV
CISA has evidence of exploitation in the wild
- CISA SSVC assessment
Exploitation: active · Automatable: yes · Technical impact: total
- CISA remediation deadline
Due date for US federal agencies to patch
- Record last updated
- EPSS reached 10%
FIRST estimates at least a 10% chance of exploitation in the next 30 days
Affected versions
- Fortinet FortiSwitchManager
From 7.2.0 · through 7.2.6; From 7.0.0 · through 7.0.5
- Fortinet FortiOS
From 7.6.0 · through 7.6.3; From 7.4.0 · through 7.4.8; From 7.2.0 · through 7.2.11; From 7.0.0 · through 7.0.17
- Fortinet FortiProxy
From 7.6.0 · through 7.6.3; From 7.4.0 · through 7.4.10; From 7.2.0 · through 7.2.14; From 7.0.0 · through 7.0.21
References 1
fortiguard.fortinet.com
Questions about CVE-2025-59718
What does this mean?
An unauthenticated attacker can bypass FortiCloud SSO login authentication by sending a crafted SAML message. That can give administrative login access to the device.Source: fortiguard.fortinet.com
Am I affected, and how do I check?
Listed ranges are FortiOS 7.6.0-7.6.3, 7.4.0-7.4.8, 7.2.0-7.2.11 and 7.0.0-7.0.17; FortiProxy 7.6.0-7.6.3, 7.4.0-7.4.10, 7.2.0-7.2.14 and 7.0.0-7.0.21; and FortiSwitchManager 7.2.0-7.2.6 and 7.0.0-7.0.5. Only devices with FortiCloud SSO login enabled are in scope, which can be checked under System -> Settings for 'Allow administrative login using FortiCloud SSO' or with the CLI setting admin-forticloud-sso-login.Source: fortiguard.fortinet.com
What should I do about it?
The advisory says to upgrade to 7.6.4 or above. Until the upgrade is applied, turning off FortiCloud login is the documented workaround.Source: fortiguard.fortinet.com
Is it being exploited?
Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2025-12-16, which means it has evidence of attacks. No public exploit code is tracked.Source: cisa.gov, cve.now feed data
What if there's no patch?
Turn off the FortiCloud login feature. In the GUI, set 'Allow administrative login using FortiCloud SSO' to Off under System -> Settings. From the CLI, run: config system global, set admin-forticloud-sso-login disable, end.Source: fortiguard.fortinet.com