high Known exploitedREV. 01

CVE-2026-20349Cisco ASA/FTD SSL VPN — heap inspection flaw, unauthenticated DoS

Cisco Secure Firewall Adaptive Security Appliance (ASA) and Threat Defense (FTD) mishandle errors in the remote-access virtual private network (VPN) web service: one crafted, unauthenticated web request reloads the device, taking it offline. Exploited in the wild.

YOUR NEXT MOVE

Apply Cisco's fix or mitigations from advisory cisco-sa-asaftd-vpn-dos-dzv4mQFF now; limit internet exposure of the remote-access VPN service and watch for unexpected reloads.

Read the risk

THE VITAL STATS
CVSS score
8.6/ 10
CVSS v3.1
EPSS probability
2%
Likelihood of exploitation
Attack complexity
Low
Conditions needed to exploit
Known exploited
Yes — CISA KEV
CVE published
2026-08-11
Added to KEV
2026-08-11
Exploit published
Not recorded
Confidence
medium
Kill chain
impact
MITRE ATT&CK
T1499.004
Severity
high

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

Attacker needsNetwork access to the Remote Access SSL VPN service on an affected ASA or FTD device; no credentials or user interaction needed.

Behind the card

3 REFERENCES
Field-level provenanceTRACE THE SOURCES +

Which source supports each field, when it was retrieved, and who extracted it.

FieldsSourceRetrievedExtractorConfidence
cvss, exploitation.attack_complexity, exploitation.exploit_available, references, published_atnvd.nist.gov2026-09-22scrty-crds-pipeline/0.1high
exploitation.known_exploited, exploitation.kev_addedcisa.gov2026-09-22scrty-crds-pipeline/0.1high
epssapi.first.org2026-09-22scrty-crds-pipeline/0.1high
title, summary, severity, remediation, mitre_attack, kill_chain, recommended_action, confidence, tags, exploitation.prerequisitesnvd.nist.gov2026-09-22claude-codehigh

Printing history

THE RECORD
  1. r1Initial base card

First printing. This card has not been reprinted since publication.

crds:cve-2026-20349 · CRDS 0.1 · Issued 2026-09-22