# CVE-2026-20025: Cisco ASA and FTD Software heap corruption in OSPF protocol

Source: https://junglewise.ai/threats/cve-2026-20025-cisco-asa-and-ftd-software-heap-corruption-in-ospf-protocol  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-03-04. Updated: 2026-06-05  
License: CC BY 4.0 with a link back

CVE-2026-20025 · Severity: medium · CVSS 6.8 · Published 2026-03-04

A vulnerability in Cisco's firewall software could allow an attacker on the same local network to crash the device. This affects the OSPF routing protocol, which is used to manage network traffic paths. If exploited, the firewall will restart unexpectedly, causing a temporary loss of network connectivity and security protection.

Technologies: [Cisco Adaptive Security Appliance Software](https://junglewise.ai/threats/technologies/secure-firewall-asa-software), [Cisco Firepower Threat Defense Software](https://junglewise.ai/threats/technologies/firepower-threat-defense-software). Vendors: [Cisco](https://junglewise.ai/threats/vendors/cisco).

## Quick answers

**Is CVE-2026-20025 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-20025 being exploited in the wild.

**How severe is CVE-2026-20025?** Medium severity, with a CVSS score of 6.8, published 4 March 2026.

**Which products and versions are affected?** Cisco Adaptive Security Appliance Software 9.12.1 to 9.16.4.85, 9.17.1 to 9.18.4.66, 9.19.1 to 9.20.4, 9.22.1.1 to 9.22.2.4, 9.23.1 to 9.23.1.7; Cisco Firepower Threat Defense Software 6.4.0 to 7.0.9, 7.1.0 to 7.2.11, 7.3.0 to 7.4.3, 7.6.0 to 7.6.4, 7.7.0 to 7.7.11.

**Is there a fix for CVE-2026-20025?** 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-2026-20025 attacked?** It is attacked from the adjacent network, in an operating system.

**Am I affected by CVE-2026-20025?** Check whether you run Cisco Adaptive Security Appliance Software or Cisco Firepower Threat Defense Software 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

The vulnerability exists in the OSPF protocol implementation of Cisco ASA and FTD software due to insufficient input validation when processing OSPF link-state update (LSU) packets. An authenticated, adjacent attacker with knowledge of the OSPF secret key can send crafted LSU packets to trigger an integer overflow (CWE-190) and subsequent heap corruption. This corruption leads to an unexpected device reload, resulting in a denial of service (DoS) condition. The vulnerability is reachable via the adjacent network (Layer 2) and requires valid OSPF authentication credentials if enabled. Cisco has released software updates to address this issue; no workarounds are available.

## Affected products

- Cisco Adaptive Security Appliance (ASA) Software 9.12.1 to 9.16.4.85, 9.17.1 to 9.18.4.66, 9.19.1 to 9.20.4, 9.22.1.1 to 9.22.2.4, 9.23.1 to 9.23.1.7
- Cisco Firepower Threat Defense (FTD) Software 6.4.0 to 7.0.9, 7.1.0 to 7.2.11, 7.3.0 to 7.4.3, 7.6.0 to 7.6.4, 7.7.0 to 7.7.11

## Timeline

- 2026-03-04: advisory: Initial publication by Cisco
- 2026-03-04: disclosed
- 2026-06-05: other: NVD analysis and CPE information updated

## References

- [https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-ospf-ZH8PhbSW](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-ospf-ZH8PhbSW)

## Related threats

- [Cisco Secure Firewall ASA and FTD denial of service in SSL VPN](https://junglewise.ai/threats/cve-2026-20349-cisco-secure-firewall-asa-and-ftd-denial-of-service-in-ssl-vpn)
- [Cisco ASA and FTD Request Smuggling in VPN Web Services](https://junglewise.ai/threats/cve-2026-20069-cisco-asa-and-ftd-request-smuggling-in-vpn-web-services)
- [Cisco ASA and FTD buffer overflow in VPN web server](https://junglewise.ai/threats/cve-2025-20333-cisco-asa-and-ftd-buffer-overflow-in-vpn-web-server)