FortiCloud SSO authentication bypass in Fortinet FortiWeb
CVE-2025-59719 is an improper verification of cryptographic signature vulnerability in Fortinet FortiWeb’s FortiCloud single sign-on (SSO) authentication flow. According to the provided content, affected versions are FortiWeb 8.0.0, 7.6.0 through 7.6.4, and 7.4.0 through 7.4.9. The flaw allows an unauthenticated attacker to submit a crafted SAML response message that is accepted despite improper signature verification, resulting in bypass of FortiCloud SSO login authentication when that feature is enabled on the device.
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Impact, mitigation & remediation
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Impact
What an attacker gets, and what they’ve been doing with it.
Mitigation
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Remediation
Patch, then assume compromise.
Exploits
No valid public exploits. Mallory filtered out 1 candidate as fakes, detection scripts, or README-only repos.
All candidate exploits were filtered out by Mallory's validation.
Affected products & vendors
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Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
Recent activity
171 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
FortiGate vulnerability possibly used in the FortiBleed campaign; described in context as one of the older unpatched flaws enabling authentication bypass and takeover of devices.
A FortiNet SSO vulnerability referenced as leading to full system compromise.
A FortiNet SSO vulnerability that, together with CVE-2025-59718, can lead to full system compromise.
Fortinet states this issue may have been used to collect credentials involved in the FortiBleed campaign, but the article provides no technical details about the flaw itself.
The version that knows your environment.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.