CVSS base score: 9.1 (Critical) vendor CNA · v3.1
Score assigned by the vendor's own CVE Numbering Authority (CNA); CISA's Vulnrichment program adds a score only when the CNA omits one.
Fortinet Multiple Products Improper Verification of Cryptographic Signature Vulnerability
Vendor: Fortinet Product: Multiple Products
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.
Each milestone comes from a different source, so gaps between them are gaps in what those sources publish, not evidence that nothing happened. EPSS history for this CVE holds 53 points from 2025-12-13, tracked daily from 2026-09-09; earlier points are weekly, which dates a spike to within a week. Peak probability 68.7% on 2026-08-29.
Check whether a specific version is affected →
What each source publishes about which product versions carry this vulnerability, kept as written rather than merged. Absence here means no source has published applicability data, not that nothing is affected.
No mentions found in monitored research blogs or news feeds.
Coverage across public collections only: Nuclei and OpenVAS NVT (scan);
Snort and Suricata ET Open (network); Sigma and YARA (host/SIEM);
Metasploit, Exploit-DB and public GitHub repositories (exploit). Absence
here means nothing public was found, not that detection is impossible.
GitHub PoC repositories are collected automatically by
PoC-in-GitHub (CC0) and are not vetted:
some are fakes and some are malware. Treat them as evidence that code was
published, not as code to run.
OpenVAS coverage derives from the Greenbone Community Feed, made available
under the Open Database License (ODbL) v1.0;
its individual Vulnerability Tests are licensed
GNU GPL v2.
| Source | Date | Record |
|---|---|---|
| CISA Vulnrichment | 2025-12-09 | source record → |
| CISA KEV | 2025-12-16 | source record → |
| Date | Advisory | Issuer |
|---|---|---|
| 2026-01-28 | Fortinet Releases Guidance to Address Ongoing Exploitation of Authentication Bypass Vulnerability CVE-2026-24858 | CISA |
No exploit-tool sightings recorded for this CVE.
Evidence tiers are explained on the About page — a merged Metasploit module is far stronger evidence than a distro package mention.
CVE.org record → NVD entry → CISA KEV catalog → FortiGuard Labs → Rapid7 AttackerKB →