CVE-2025-62675 in FortiProxy and FortiOS
An Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting') vulnerability [CWE-113] vulnerability in Fortinet FortiOS 7.6.0 through 7.6.4, FortiOS 7.4 all versions, FortiOS 7.2 all versions, FortiProxy 7.6.0 through 7.6.4, FortiProxy 7.4 all versions, FortiProxy 7.2 all versions may allow an attacker in possession of a valid web filter override token to inject arbitrary headers via tricking a user into clicking on a crafted link.
Quick answer
Fortinet FortiProxy and FortiOS should be reviewed and updated if it matches the affected versions. The recommended fix is to apply the vendor-supported patched version or the mitigation steps below, then retest the public website with Fixnx.
Who is affected
Affected versions
- FortiOS 7.6.0 through 7.6.4, 7.4 all versions, and 7.2 all versions
- FortiProxy 7.6.0 through 7.6.4, 7.4 all versions, and 7.2 all versions
Fixed versions
- Latest vendor-supported fixed release listed in Fortinet advisory FG-IR-26-152
How to fix it
CVE-2025-62675 affects FortiProxy and FortiOS. In simple terms, an attacker may inject unsafe HTTP headers in some flows. Fix it by updating to Latest vendor-supported fixed release listed in Fortinet advisory FG-IR-26-152. If this system is online or used by admins, treat the fix as urgent.
- Find every place where FortiProxy and FortiOS is installed or used.
- Check if the version matches: FortiOS 7.6.0 through 7.6.4, 7.4 all versions, and 7.2 all versions; FortiProxy 7.6.0 through 7.6.4, 7.4 all versions, and 7.2 all versions.
- Update or apply the vendor fix: Latest vendor-supported fixed release listed in Fortinet advisory FG-IR-26-152.
- If you cannot update today, allow only trusted users and trusted networks.
- Turn off the affected feature or plugin if the vendor says that is safe to do.
- Check logs for crashes, strange requests, new admin actions, or unexpected access.
- Change secrets or passwords if you think data or admin access may have been exposed.
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Verify the fix
- Confirm the installed version or mitigation matches: Latest vendor-supported fixed release listed in Fortinet advisory FG-IR-26-152.
- Confirm the affected feature is no longer exposed to untrusted users.
- Run the affected workflow again and make sure it still works.
- Review logs again after the fix for repeated suspicious activity.
- Run a new Fixnx scan if this software is part of a public website.
- Save the advisory link and proof of the fix in your change record.
Related categories
Trusted references
FAQ
What is affected by CVE-2025-62675?
Fortinet FortiProxy and FortiOS versions listed as affected should be reviewed: FortiOS 7.6.0 through 7.6.4, 7.4 all versions, and 7.2 all versions, FortiProxy 7.6.0 through 7.6.4, 7.4 all versions, and 7.2 all versions.
What should I fix first?
Start with internet-facing sites, admin panels, login flows, plugins, themes, modules, packages, and systems that process user-controlled input or sensitive data.
How do I confirm the fix worked?
Apply the patched version or mitigation, clear caches where relevant, retest the affected workflow, and run a new Fixnx scan to verify public website exposure signals.
How are Fixnx security risk categories chosen?
Fixnx keeps one canonical risk page and assigns only broad, relevant categories such as ecosystem, technology area, or vulnerability class.