# CVE-2026-76413: Cisco Secure FMC SSO token forgery in ASDM handler

Source: https://junglewise.ai/threats/cve-2026-76413-cisco-secure-fmc-sso-token-forgery-in-asdm-handler  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-16. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-76413 · Severity: high · CVSS 8.2 · Published 2026-09-16

Cisco Secure Firewall Management Center (FMC) is a centralized management platform for Cisco firewall deployments. A vulnerability in its single sign-on system allows unauthenticated attackers to forge administrator credentials, gaining unauthorized access and potentially locking out legitimate administrators from management functions indefinitely.

Technologies: [Cisco Secure Firewall Management Center](https://junglewise.ai/threats/technologies/secure-firewall-management-center). Vendors: [Cisco](https://junglewise.ai/threats/vendors/cisco).

## Quick answers

**Is CVE-2026-76413 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-76413 being exploited in the wild.

**How severe is CVE-2026-76413?** High severity, with a CVSS score of 8.2, published 16 September 2026.

**Which products and versions are affected?** Cisco Secure Firewall Management Center Multiple versions (see Cisco advisory for specific affected releases).

**Is there a fix for CVE-2026-76413?** 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-2026-76413 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-76413?** Check whether you run Cisco Secure Firewall Management Center 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 ASDM (Adaptive Security Device Manager) SSO token handler within Cisco Secure FMC Software, stemming from improper management and validation of SSO tokens. An unauthenticated, remote attacker can exploit this by performing session token forgery techniques to impersonate the ASDM administrator user without valid credentials. The attack has no preconditions (no authentication required) and is network-reachable. Successful exploitation grants full administrator access and enables attackers to prevent legitimate administrators from accessing the system through repeated login cycles. Cisco has released software patches to address this vulnerability, and no workarounds are available.

## Affected products

- Cisco Secure Firewall Management Center Multiple versions (see Cisco advisory for specific affected releases)

## Timeline

- 2026-09-16: disclosed: Cisco Security Advisory cisco-sa-fmc2-multivulns-HXgcqRG published

## References

- [https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc2-multivulns-HXgcqRG](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc2-multivulns-HXgcqRG)

## Related threats

- [Cisco Secure FMC privilege escalation in remote diagnostics debugger](https://junglewise.ai/threats/cve-2026-76412-cisco-secure-fmc-privilege-escalation-in-remote-diagnostics)
- [Cisco Secure Firewall software resource lifecycle vulnerability](https://junglewise.ai/threats/cve-2026-20336-cisco-secure-firewall-software-resource-lifecycle-vulnerability)
- [Cisco Secure FMC and FTD sftunnel authentication bypass](https://junglewise.ai/threats/cve-2026-20323-cisco-secure-fmc-and-ftd-sftunnel-authentication-bypass)
- [Cisco Secure FMC and FTD memory exhaustion in sftunnel](https://junglewise.ai/threats/cve-2026-20295-cisco-secure-fmc-and-ftd-memory-exhaustion-in-sftunnel)
- [Cisco Secure FMC Software unsecured deserialization in sftunnel](https://junglewise.ai/threats/cve-2026-20341-cisco-secure-fmc-software-unsecured-deserialization-in-sftunnel)