CVE-2026-20342

Cisco Secure Firewall Management Center Software Low Privileged Arbitrary File Download Vulnerability

No known exploitation. EPSS puts it in the 48th percentile. No fix published yet.

CVSS 3.17.7High EPSS percentile48th0.6% chance in 30 days CISA KEVNot listedNo confirmed exploitation
No public exploit known FixNone yetNo fix or workaround published

Check it yourself

OpenVAS · 1 check

e.g. OID 1.3.6.1.4.1.25623.1.0.157957

Run the check

Published 2026-09-16Updated 2026-09-18Sources: CVE.org, NVD

NVD CVE.org

What to do

No fixed build or workaround is published yet. Limit exposure and watch for a patch.

Cisco Secure Firewall Management CenterAffected: 7.0.0Upgrade to: not statedAffected: 7.0.0.1Upgrade to: not statedAffected: 7.0.1Upgrade to: not statedAffected: 7.0.1.1Upgrade to: not stated + 64 more branchesStated by: CVE record

Versions as the sources state them. Full version matrix after sign-in

Steps

Written by AI from the record

Check whether your organization runs Cisco Secure Firewall Management Center and identify all accounts with Security Analyst or higher access.
There is no published fixed version yet; ask Cisco or your support provider for the official remediation and upgrade guidance for CVE-2026-20342.
Until a fix is available, restrict Security Analyst access to trusted staff, remove unused accounts, and review recent file-download activity.
Rotate passwords and access tokens if you find unexpected file downloads or suspicious account use.

May need vendor or contractor work

Check it yourselfA free OpenVAS check exists for this CVE. Run it against your hosts.Is your organisation exposed?Request an assessment to establish which checks fit your systems.

What it is

From the CVE record

A vulnerability in a specific file download API of Cisco Secure FMC Software could allow an authenticated, remote attacker to download arbitrary files from an affected system. This vulnerability exists because user input is not being sanitized. An attacker could exploit this vulnerability by sending a crafted HTTPS request. A successful exploit could allow the attacker to download arbitrary files from the affected system. To exploit this vulnerability, the attacker must have valid credentials for a user account with at least the role of Security Analyst (read-only).

In plain language

Written by AI from the record

Cisco Secure Firewall Management Center has a flaw that lets a low-level account download files it should not see, so businesses using it should act now.

Authenticated arbitrary file read through the Cisco Secure Firewall Management Center file-download API due to improper authorization/input handling (CWE-639).

If you're affected

Sensitive file exposure
Configuration theft
Network information exposure
Follow-on system compromise

What is it

This is a weakness in a file-download feature of Cisco Secure Firewall Management Center. It is like giving a visitor a key to one filing cabinet, but allowing that key to open other cabinets containing information they were never meant to access.

Who is affected

This matters to you if you run Cisco Secure Firewall Management Center. An attacker needs valid credentials for an account with at least the read-only Security Analyst role, so it is only a risk if they already have that level of access.

How urgent is it

A public exploit is available, making it easier for attackers who obtain a low-level account to try downloading sensitive files. Treat this as urgent: reduce unnecessary account access and obtain Cisco's remediation guidance immediately.

What to do — in detail

Confirm exposure by inventorying Cisco Secure Firewall Management Center deployments and reviewing whether the file-download API is reachable by users with the Security Analyst role or greater. Review account lists, authentication logs, and API or web-access logs for unusual download requests, especially requests for unexpected file paths.

No fixed version or patch has been published in the available findings. Contact Cisco support for product-specific remediation guidance and track the advisory for a supported fixed release; do not assume an upgrade target until Cisco publishes one.

If patching is delayed, remove or disable unused low-privileged accounts, limit Security Analyst access to named trusted staff, enforce strong authentication, and restrict management access to approved administrative networks. Investigate unexpected downloads as a possible data-exposure incident, then rotate affected credentials and access tokens. CISA has not added this CVE to the KEV catalog, so there is no CISA remediation due date in the findings.

Technical context

CVE-2026-20342 has CVSS 7.7 High (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N). It is an authenticated remote arbitrary-file-download issue in a specific HTTPS file-download API, attributed to CWE-639; exploitation requires valid credentials with at least the Security Analyst read-only role. Public exploit code is available. EPSS is 0.5% at the 45th percentile with a flat trend. It is not listed in CISA KEV; the findings do not confirm exploitation in the wild.

This is a general assessment based on public vulnerability data. It does not account for your specific infrastructure — when in doubt, consult a security specialist.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS48th

CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

No public exploit or proof of concept found in the sources we track.

EPSS

0.6% chance of exploitation activity in the next 30 days, which ranks it in the 48th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

7 events over 36 days, from the signal feeds we watch.

2026-10-22OpenVAS check added
2026-09-18Record updated
2026-09-17Record updated
2026-09-16Publishedweakness classified, att&ck mapped, record updated

Affected products

Ciscocommercial · USaka cisco systems inc., cisco systems
- Cisco Secure Firewall Management Center (FMC)Networking Infrastructure

Technical detail

CVSS 3.1 vector

Open in the CVSS calculator

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

Scored 7.7 by NVD.

How it is reached

Attack Vector NetworkExploitable remotely over the network without any special conditions
Attack Complexity LowNo special conditions — the attack can be reliably reproduced
Privileges Required LowRequires basic user-level privileges
User Interaction NoneNo user interaction needed — fully automated exploitation

Scope

Scope ChangedThe exploit can affect other components (e.g. sandbox escape, host compromise from VM)

Impact if exploited

Confidentiality HighTotal information disclosure — all data in the component is compromised
Integrity NoneNo integrity impact
Availability NoneNo availability impact

Weaknesses

CWE-639No name in the record

ATT&CK techniques

Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.

Initial AccessT1078Valid Accountshigh confidence

Sources

References in the record

sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc-mulivulns-4PsnFwvx

In the news

Cisco Warns of New Zero-Day ISE Auth Bypass (CVSS 10.0) Exploited in Active AttacksThe Hacker News · 2026-09-17

Watch the software you run.

My Stack ranks new CVEs for your products by real-world exploitation, so the next serious one reaches you without reading every advisory.

We'll flag the next CVE, public exploit or patch for Cisco, not every advisory.

A free account adds

The full version matrix and every affected product
Exploit links, proofs of concept and Metasploit modules
Email alerts for the products you watch
The same data over REST API, MCP and CLI

Create a free account