Is CVE-2025-53843 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2025-53843 being exploited in the wild.

How severe is CVE-2025-53843?

High severity, with a CVSS score of 7.5, published 18 November 2025.

Which products and versions are affected?

Fortinet FortiOS 7.6.0 through 7.6.3, 7.4.0 through 7.4.8, 7.2 all versions, 7.0 all versions, 6.4 all versions; Fortinet FortiSwitchManager All versions; Siemens Ruggedcom Ape1808 All versions with Fortinet NGFW < V7.4.9 or < V7.6.6.

Is there a fix for CVE-2025-53843?

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-2025-53843 attacked?

It is attacked over the network, in an operating system.

Am I affected by CVE-2025-53843?

Check whether you run Fortinet FortiOS, Fortinet FortiSwitchManager or Siemens Ruggedcom Ape1808 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.

CVE-2025-53843: Fortinet FortiOS stack buffer overflow in CAPWAP daemon

Q: Is there a fix for CVE-2025-53843?

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.

Q: How is CVE-2025-53843 attacked?

It is attacked over the network, in an operating system.

Q: Am I affected by CVE-2025-53843?

Check whether you run Fortinet FortiOS, Fortinet FortiSwitchManager or Siemens Ruggedcom Ape1808 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.

CVE-2025-53843 · Severity: high · CVSS 7.5 · Published 2025-11-18

A security vulnerability exists in the software used to manage Fortinet firewalls and wireless access points. An attacker who can pose as a legitimate network device (like a wireless access point) could potentially take control of the firewall. This could lead to unauthorized access to the network, data theft, or a complete disruption of security operations.

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

Quick answers

Is CVE-2025-53843 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2025-53843 being exploited in the wild.
How severe is CVE-2025-53843?: High severity, with a CVSS score of 7.5, published 18 November 2025.
Which products and versions are affected?: Fortinet FortiOS 7.6.0 through 7.6.3, 7.4.0 through 7.4.8, 7.2 all versions, 7.0 all versions, 6.4 all versions; Fortinet FortiSwitchManager All versions; Siemens Ruggedcom Ape1808 All versions with Fortinet NGFW < V7.4.9 or < V7.6.6.
Is there a fix for CVE-2025-53843?: 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-2025-53843 attacked?: It is attacked over the network, in an operating system.
Am I affected by CVE-2025-53843?: Check whether you run Fortinet FortiOS, Fortinet FortiSwitchManager or Siemens Ruggedcom Ape1808 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 stack-based buffer overflow vulnerability (CWE-121/CWE-124) exists in the CAPWAP (Control and Provisioning of Wireless Access Points) daemon of FortiOS and FortiSwitchManager. The flaw is triggered when the daemon processes specially crafted packets. To exploit this, an attacker must be authenticated and capable of posing as an authorized FortiAP or FortiExtender device. Successful exploitation allows for arbitrary code execution or command execution with the privileges of the CAPWAP process. While stack protection and ASLR increase the difficulty of exploitation, the vulnerability poses a significant risk if 'auto-auth-extension-device' is enabled, as it allows unauthorized devices to be automatically trusted. Patches are available in FortiOS versions 7.6.4 and 7.4.9.

Affected products

Fortinet FortiOS 7.6.0 through 7.6.3, 7.4.0 through 7.4.8, 7.2 all versions, 7.0 all versions, 6.4 all versions
Fortinet FortiSwitchManager All versions
Siemens RUGGEDCOM APE1808 All versions with Fortinet NGFW < V7.4.9 or < V7.6.6

Timeline

2025-11-18: disclosed: Initial publication by Fortinet
2025-11-18: advisory
2025-11-21: other: Workarounds added to advisory

References

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