CVE-2025-25249Network attack vector

Unauthenticated code execution via crafted packet heap overflow

Published Jan 13, 2026 · Updated Jan 13, 2026

Heap-based buffer overflow in Fortinet FortiOS, FortiSASE, and FortiSwitch Manager allows remote attackers to execute code via crafted packets. Fortinet has not disclosed the affected packet-processing component, protocol, or length-handling operation that writes beyond a heap allocation. Network access without authentication or user interaction is sufficient, although exploitation requires high complexity and grants code execution on the affected service or appliance.

CVSS severity8.1
High
EPSS probability2.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in Fortinet FortiOS, FortiSASE, and FortiSwitch Manager allows remote attackers to execute code via crafted packets. Fortinet has not disclosed the affected packet-processing component, protocol, or length-handling operation that writes beyond a heap allocation. Network access without authentication or user interaction is sufficient, although exploitation requires high complexity and grants code execution on the affected service or appliance.

The record

CVE
CVE-2025-25249
Published
Jan 13, 2026
Updated
Jan 13, 2026
Vendor
Fortinet
Product
FortiSASE
Classifications
CWE-122, CWE-787, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=25.1.a.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Fortinet · FortiSASEversion=25.1.a.2
Fortinet · FortiOSversion=7.2.4 <=7.2.11; version=7.4.0 <=7.4.7; version=7.6.0 <=7.6.2
Fortinet · FortiSwitch Managerversion=7.2.2 <=7.2.5

Published CVSS scores

8.1Fortinet, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-122Heap-based Buffer Overflow
CWE-787Out-of-bounds Write
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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