CVE-2025-25249: Fortinet FortiOS heap overflow in cw_acd daemon

CVE-2025-25249 · Severity: critical · CVSS 8.1 · Exploited in the wild · Published 2026-01-13

Fortinet FortiOS and related security appliances contain a heap-based buffer overflow vulnerability in packet processing that allows remote attackers to execute arbitrary code. Exploitation has been observed in the wild, making this an active threat to organizations relying on these products for network security and management.

Technologies: Fortinet FortiOS, Fortinet Fortisase, Fortinet FortiSwitchManager, Siemens Ruggedcom Ape1808. Vendors: Fortinet, Siemens.

Quick answers

Is CVE-2025-25249 exploited in the wild?
Yes. CVE-2025-25249 is known to be exploited in the wild, first recorded on 9 September 2026. Treat it as urgent.
How severe is CVE-2025-25249?
Critical severity, with a CVSS score of 8.1, published 13 January 2026.
Which products and versions are affected?
Fortinet FortiOS 7.6.0 through 7.6.3, 7.4.0 through 7.4.8, 7.2.0 through 7.2.11, 7.0.0 through 7.0.17, 6.4 all versions; Fortinet Fortisase 25.2.b, 25.1.a.2; Fortinet FortiSwitchManager 7.2.0 through 7.2.6, 7.0.0 through 7.0.5; Siemens Ruggedcom Ape1808 Versions with Fortinet NGFW < V7.4.9.
Is there a fix for CVE-2025-25249?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2025-25249 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2025-25249?
Check whether you run Fortinet FortiOS, Fortinet Fortisase, Fortinet FortiSwitchManager or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A heap-based buffer overflow exists in the packet processing functionality of Fortinet FortiOS, FortiSwitchManager, and FortiSASE. The vulnerability is triggered when the affected products process specially crafted network packets, leading to memory corruption on the heap. An unauthenticated remote attacker on the network can exploit this vulnerability without user interaction to achieve arbitrary code execution with the privileges of the vulnerable process. The vulnerability is being actively exploited in the wild, indicating broad availability of exploit code or techniques.

Affected products

  • Fortinet FortiOS
  • Fortinet FortiSwitchManager
  • Fortinet FortiSASE

Timeline

  • 2026-09-09: disclosed
  • exploited: Active exploitation reported in the wild

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