Medium

Lua code injection leading to root RCE in Cisco Secure Firewall ASA/FTD CLI commands

IdentifiersCVE-2026-20008CWE-94

CVE-2026-20008 is a Lua code injection vulnerability in a small subset of CLI commands in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software. The issue is caused by improper sanitization of user-supplied input passed as a parameter to affected CLI commands, allowing an authenticated local attacker to submit crafted, valid Lua code. Successful exploitation results in injection and execution of Lua code on the underlying operating system with root privileges, enabling arbitrary code execution as root.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

An authenticated local attacker with Administrator credentials can achieve arbitrary code execution as the root user on the underlying operating system of affected Cisco Secure Firewall ASA/FTD devices. This can enable full device compromise, including modification of system configuration and software, disabling or subverting security controls, and potential pivoting to other networks reachable from the appliance.

Mitigation

If you can’t patch tonight, do this now.

Restrict and monitor administrative (CLI) access to ASA/FTD devices (e.g., limit management-plane access to dedicated admin networks/jump hosts, enforce least privilege for administrative accounts, and audit CLI usage). Because exploitation requires authenticated Administrator access and local CLI interaction, reducing exposure of management interfaces and tightening administrative access controls reduces risk until patches can be applied.

Remediation

Patch, then assume compromise.

Apply Cisco-provided software updates that address CVE-2026-20008 for Cisco Secure Firewall ASA and Cisco Secure Firewall FTD. Upgrade to a fixed release as specified in the relevant Cisco Security Advisory for the ASA/FTD Lua injection issue.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

Cisco SystemsAdaptive Security Appliance Softwareoperating_system

Cisco SystemsFirepower Threat Defense Softwareapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

3 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

3 SOURCESView more in app

cisco security centerNews

Mar 4, 2026

Cisco Event Response: March 2026 Cisco Secure Firewall ASA, Secure FMC, and Secure FTD Software Security Advisory Bundled Publication

Lua code injection vulnerability affecting Cisco ASA and Cisco Secure Firewall Threat Defense (FTD).

What this page doesn’t show

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Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity1

Community discussion across Reddit, Mastodon, and other social sources.

EXTERNAL REFERENCES

MITRE CVE

cve.org · CVE-2026-20008

NVD

nvd.nist.gov/vuln/detail/CVE-2026-20008

MITRE CWE · CWE-94

cwe.mitre.org

Vendor Advisory

sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-luainject-VescqgmS