How severe is CVE-2025-25249?

CVE-2025-25249 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-25249 being actively exploited?

Yes. CVE-2025-25249 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2026-09-09, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2025-25249?

CVE-2025-25249 primarily affects Fortinet Fortios. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2025-25249?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

Does CVE-2025-25249 have an EU (EUVD) identifier?

Yes. CVE-2025-25249 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-2223.

When was CVE-2025-25249 published?

CVE-2025-25249 was published on 2026-01-13 and last updated on 2026-09-10.

CVE-2025-25249

CVE-2025-25249 is a high-severity vulnerability in Fortinet Fortios with a CVSS 3.x base score of 8.1. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2026-09-09). The underlying weakness is classified as CWE-787.

Key facts

Severity: High (CVSS 3.x base score 8.1)
EPSS exploit prediction: 4% (90th percentile)
Actively exploited: Yes — listed in CISA KEV (added 2026-09-09)
EU (EUVD) id: EUVD-2026-2223
Weakness: CWE-787
Affected product: Fortinet Fortios
Published: 2026-01-13
Last modified: 2026-09-10

Description

A heap-based buffer overflow vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2.0 through 7.2.11, FortiOS 7.0.0 through 7.0.17, FortiOS 6.4 all versions, FortiSwitchManager 7.2.0 through 7.2.6, FortiSwitchManager 7.0.0 through 7.0.5 allows attacker to execute unauthorized code or commands via specially crafted packets

Frequently asked questions

What is CVE-2025-25249?: A heap-based buffer overflow vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2.0 through 7.2.11, FortiOS 7.0.0 through 7.0.17, FortiOS 6.4 all versions, FortiSwitchManager 7.2.0 through 7.2.6, FortiSwitchManager 7.0.0 through 7.0.5 allows attacker to execute unauthorized code or commands via specially crafted packets
How severe is CVE-2025-25249?: CVE-2025-25249 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-25249 being actively exploited?: Yes. CVE-2025-25249 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2026-09-09, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2025-25249?: CVE-2025-25249 primarily affects Fortinet Fortios. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-25249?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2025-25249 have an EU (EUVD) identifier?: Yes. CVE-2025-25249 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-2223.
When was CVE-2025-25249 published?: CVE-2025-25249 was published on 2026-01-13 and last updated on 2026-09-10.

References

Affected products (5)

cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*
cpe:2.3:a:fortinet:fortiswitchmanager:*:*:*:*:*:*:*:*
cpe:2.3:a:fortinet:fortisase:25.1.39:*:*:*:-:*:*:*
cpe:2.3:a:fortinet:fortisase:25.1.51:*:*:*:-:*:*:*
cpe:2.3:o:siemens:ruggedcom_ape1808_firmware:-:*:*:*:*:*:*:*

More vulnerabilities in Fortinet Fortios

CVE-2005-3057 — Critical (CVSS 10.0): The FTP component in FortiGate 2.8 running FortiOS 2.8MR10 and v3beta, and other versions before 3.0 MR1, allows remote…
CVE-2026-24858 — Critical (CVSS 9.8): An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] vulnerability in Fortinet…
CVE-2025-59718 — Critical (CVSS 9.8): A improper verification of cryptographic signature vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0…
CVE-2025-22252 — Critical (CVSS 9.8): A missing authentication for critical function in Fortinet FortiProxy versions 7.6.0 through 7.6.1, FortiSwitchManager…
CVE-2023-25610 — Critical (CVSS 9.8): A buffer underwrite ('buffer underflow') vulnerability in the administrative interface of Fortinet FortiOS version…
CVE-2024-55591 — Critical (CVSS 9.8): An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] affecting FortiOS version 7.0.0…

All CVEs affecting Fortinet Fortios →

Other CWE-787 (Out-of-bounds Write) vulnerabilities

CVE-2026-42369 — Critical (CVSS 10.0): GV-VMS V20 is a Video Monitoring Software used to gather the feeds of many surveillance cameras and manage other…
CVE-2026-4746 — Critical (CVSS 10.0): Out-of-bounds Write vulnerability in timeplus-io proton (base/poco/Foundation/src‎ modules). This vulnerability is…
CVE-2025-43300 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 15.8.5 and iPadOS…
CVE-2025-24201 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved checks to prevent unauthorized actions. This issue is fixed in…
CVE-2024-42479 — Critical (CVSS 10.0): llama.cpp provides LLM inference in C/C++. The unsafe `data` pointer member in the `rpc_tensor` structure can cause…
CVE-2024-39791 — Critical (CVSS 10.0): Stack-based buffer overflow vulnerabilities affecting Vonets industrial wifi bridge relays and wifi bridge…

Browse all CWE-787 (Out-of-bounds Write) vulnerabilities →