# CVE-2026-76413: Cisco Secure Firewall Management Center Software Single Sign-On Token Forgery of Administrator Account Vulnerability

> Unauthenticated attackers can forge SSO tokens to log in as administrator, potentially locking out legitimate users.

- **Severity:** High 8.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Sep 2026
- **Updated:** 17 Sep 2026
- **Also known as:** GHSA-g9vq-7qf2-jm65

## What is CVE-2026-76413?

CVE-2026-76413 is a high-severity authentication bypass vulnerability in Cisco Secure Firewall Management Center (FMC), published on 16 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in Cisco Adaptive Security Device Manager (ASDM) single sign-on (SSO) handler for Cisco Secure FMC Software could allow an unauthenticated, remote attacker to log in as the Cisco ASDM administrator user.

This vulnerability is due to improper management of the Cisco ASDM SSO token. An attacker could exploit this vulnerability by performing session token forgery techniques. A successful exploit could allow the attacker to log in as the administrator user and, by repeating this action, keep legitimate administrators locked out of the ASDM indefinitely.

Weakness: CWE-1259 (Improper Restriction of Security Token Assignment)

## Which versions are affected by CVE-2026-76413?


## How do I fix CVE-2026-76413?

No fix has been published for CVE-2026-76413 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-76413 being exploited?

There is no known exploitation of CVE-2026-76413 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-76413 and fix it if it is affected.

What it is: CVE-2026-76413 is a high-severity authentication bypass vulnerability in Cisco Secure Firewall Management Center (FMC), published on 16 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-76413 in the wild and no public exploit code.

Affected product: Cisco Secure Firewall Management Center (FMC). No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-76413/ (Markdown: https://insights.sbomify.com/CVE-2026-76413/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-76413
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-76413
- OSV: https://osv.dev/vulnerability/CVE-2026-76413

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-76413/
Summaries are generated and may contain mistakes; the official description above is the record.