Cyber Resilience

CVE-2025-62631

Fortinet Fortios 6.4.0 – 7.4.1

Published
09 December 2025
Modified
14 January 2026
Patch / advisory
View advisory
CVSS Score v3.1 5.6
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
EPSS Score 0.0029 21th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2025-62631 is a medium-severity Insufficient Session Expiration (CWE-613) vulnerability in Fortinet Fortios. Its CVSS base score is 5.6 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Valid Accounts (T1078); ranked at the 21th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-12 (Session Termination) and AC-2 (Account Management) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A07:2025 Authentication Failures

EU & UK References

Vulnerability Data

An insufficient session expiration vulnerability [CWE-613] vulnerability in Fortinet FortiOS 7.4.0, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4 all versions allows attacker to maintain access to network resources via an active SSLVPN session not terminated after a…

more

user's password change under particular conditions outside of the attacker's control

CWE(s)
CWE-613

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1078 Valid Accounts Stealth
Adversaries may obtain and abuse credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion.
attack.mitre.org →
T1078.001 Default Accounts Stealth
Adversaries may obtain and abuse credentials of a default account as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion.
attack.mitre.org →
T1078.002 Domain Accounts Stealth
Adversaries may obtain and abuse credentials of a domain account as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion.
attack.mitre.org →
T1078.003 Local Accounts Stealth
Adversaries may obtain and abuse credentials of a local account as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion.
attack.mitre.org →
Why these techniques?

Insufficient session expiration (CWE-613) allows an attacker to maintain authenticated access via an active SSLVPN session after password change, directly mapping to Valid Accounts techniques where credentials or sessions remain usable beyond intended validity.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2023-28001Same product: Fortinet Fortios
CVE-2025-25252Same product: Fortinet Fortios
CVE-2020-12812Same product: Fortinet Fortios
CVE-2023-46717Same product: Fortinet Fortios
CVE-2023-46714Same product: Fortinet Fortios
CVE-2016-1909Same product: Fortinet Fortios
CVE-2025-58325Same product: Fortinet Fortios
CVE-2024-26007Same product: Fortinet Fortios
CVE-2024-32122Same product: Fortinet Fortios
CVE-2025-53844Same product: Fortinet Fortios

Affected Assets

fortinet
fortios
6.4.0 — 7.4.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-12 Session Termination
  • IA-11 Re-authentication
  • AC-2 Account Management
Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)

—

Mitigating Controls (NIST 800-53 r5) AI

AC-12 Session Termination good match
prevent

Directly requires session termination upon events such as credential changes, eliminating the stale SSLVPN session that persists after password reset.

IA-11 Re-authentication partial match
prevent

Forces re-authentication after authenticator changes, ensuring any active VPN session tied to the old password is invalidated.

AC-2 Account Management partial match
prevent

Account management procedures can mandate immediate session invalidation and token revocation when passwords are changed.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-01 mostly match
prevents

Credential lifecycle management directly includes enforcing session expiration to prevent reuse.

PR.AA-05 mostly match
prevents

Authorization policy enforcement and review covers terminating stale sessions to limit access scope.

PR.AA-03 partial match
prevents

Authentication mechanisms can incorporate session timeout checks but do not inherently address expiration policy.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.5 Secure authentication none match
none

Automatic termination of inactive sessions and limits on connection duration shrink the window during which a hijacked or unattended authenticated session can be exploited.

References