CVE-2026-20349 CISA KEV · Actively exploitedSuited to automated attack · CISA

Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Remote Access SSL VPN Denial of Service Vulnerability

CVSS score

8.6

EPSS probability

%1.0

Risk score

0.2

Published

2 mo ago

Overview Public Exploits (0)Newsroom Vulnerability Timeline

Mitigation available

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Impact on My Inventory

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Vulnerability description

DayBreach CVE AI Research

CVE-2026-20349 has vendor, distribution, patch and security-source records on file. We can compare them and prepare an explanation linked to the evidence.

A vulnerability in the Remote Access SSL VPN service for Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition.  This vulnerability is due to insufficient error checking when processing HTTP requests. An attacker could exploit this vulnerability by sending a crafted HTTP request to the Remote Access SSL VPN service on an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-20349 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

ID	VENDOR	PRODUCT	ACTION
1	cisco	Cisco Secure Firewall Adaptive Security Appliance (ASA) Software	View
2	cisco	Cisco Secure Firewall Threat Defense (FTD) Software	View
3	cisco	adaptive security appliance software	View
4	cisco	adaptive security appliance software	View
5	cisco	adaptive security appliance software	View
6	cisco	adaptive security appliance software	View
7	cisco	adaptive security appliance software	View
8	cisco	adaptive security appliance software	View
9	cisco	adaptive security appliance software	View
10	cisco	adaptive security appliance software	View
11	cisco	adaptive security appliance software	View
12	cisco	adaptive security appliance software	View
13	cisco	adaptive security appliance software	View
14	cisco	adaptive security appliance software	View
15	cisco	adaptive security appliance software	View
16	cisco	adaptive security appliance software	View
17	cisco	adaptive security appliance software	View
18	cisco	adaptive security appliance software	View
19	cisco	adaptive security appliance software	View
20	cisco	adaptive security appliance software	View
21	cisco	adaptive security appliance software	View
22	cisco	adaptive security appliance software	View
23	cisco	adaptive security appliance software	View
24	cisco	adaptive security appliance software	View
25	cisco	adaptive security appliance software	View
26	cisco	adaptive security appliance software	View
27	cisco	adaptive security appliance software	View
28	cisco	adaptive security appliance software	View
29	cisco	adaptive security appliance software	View
30	cisco	adaptive security appliance software	View
31	cisco	adaptive security appliance software	View
32	cisco	adaptive security appliance software	View
33	cisco	adaptive security appliance software	View
34	cisco	adaptive security appliance software	View
35	cisco	adaptive security appliance software	View
36	cisco	adaptive security appliance software	View
37	cisco	adaptive security appliance software	View
38	cisco	adaptive security appliance software	View
39	cisco	adaptive security appliance software	View
40	cisco	adaptive security appliance software	View
41	cisco	adaptive security appliance software	View
42	cisco	adaptive security appliance software	View
43	cisco	adaptive security appliance software	View
44	cisco	adaptive security appliance software	View
45	cisco	adaptive security appliance software	View
46	cisco	adaptive security appliance software	View
47	cisco	adaptive security appliance software	View
48	cisco	adaptive security appliance software	View
49	cisco	adaptive security appliance software	View
50	cisco	adaptive security appliance software	View
51	cisco	adaptive security appliance software	View
52	cisco	adaptive security appliance software	View
53	cisco	adaptive security appliance software	View
54	cisco	adaptive security appliance software	View
55	cisco	adaptive security appliance software	View
56	cisco	adaptive security appliance software	View
57	cisco	adaptive security appliance software	View
58	cisco	adaptive security appliance software	View
59	cisco	adaptive security appliance software	View
60	cisco	adaptive security appliance software	View
61	cisco	adaptive security appliance software	View
62	cisco	adaptive security appliance software	View
63	cisco	adaptive security appliance software	View
64	cisco	adaptive security appliance software	View
65	cisco	adaptive security appliance software	View
66	cisco	adaptive security appliance software	View
67	cisco	adaptive security appliance software	View
68	cisco	adaptive security appliance software	View
69	cisco	adaptive security appliance software	View
70	cisco	adaptive security appliance software	View
71	cisco	adaptive security appliance software	View
72	cisco	adaptive security appliance software	View
73	cisco	adaptive security appliance software	View
74	cisco	adaptive security appliance software	View
75	cisco	adaptive security appliance software	View
76	cisco	adaptive security appliance software	View
77	cisco	adaptive security appliance software	View
78	cisco	adaptive security appliance software	View
79	cisco	adaptive security appliance software	View
80	cisco	adaptive security appliance software	View
81	cisco	adaptive security appliance software	View
82	cisco	adaptive security appliance software	View
83	cisco	adaptive security appliance software	View
84	cisco	adaptive security appliance software	View
85	cisco	adaptive security appliance software	View
86	cisco	adaptive security appliance software	View
87	cisco	adaptive security appliance software	View
88	cisco	adaptive security appliance software	View
89	cisco	adaptive security appliance software	View
90	cisco	adaptive security appliance software	View
91	cisco	adaptive security appliance software	View
92	cisco	adaptive security appliance software	View
93	cisco	adaptive security appliance software	View
94	cisco	adaptive security appliance software	View
95	cisco	adaptive security appliance software	View
96	cisco	adaptive security appliance software	View
97	cisco	adaptive security appliance software	View
98	cisco	adaptive security appliance software	View
99	cisco	adaptive security appliance software	View
100	cisco	adaptive security appliance software	View
101	cisco	adaptive security appliance software	View
102	cisco	adaptive security appliance software	View
103	cisco	adaptive security appliance software	View
104	cisco	adaptive security appliance software	View
105	cisco	adaptive security appliance software	View
106	cisco	adaptive security appliance software	View
107	cisco	adaptive security appliance software	View
108	cisco	adaptive security appliance software	View
109	cisco	adaptive security appliance software	View
110	cisco	adaptive security appliance software	View
111	cisco	adaptive security appliance software	View
112	cisco	adaptive security appliance software	View
113	cisco	adaptive security appliance software	View
114	cisco	adaptive security appliance software	View
115	cisco	adaptive security appliance software	View
116	cisco	adaptive security appliance software	View
117	cisco	adaptive security appliance software	View
118	cisco	adaptive security appliance software	View
119	cisco	adaptive security appliance software	View
120	cisco	adaptive security appliance software	View
121	cisco	adaptive security appliance software	View
122	cisco	adaptive security appliance software	View
123	cisco	adaptive security appliance software	View
124	cisco	adaptive security appliance software	View
125	cisco	adaptive security appliance software	View
126	cisco	adaptive security appliance software	View
127	cisco	adaptive security appliance software	View
128	cisco	adaptive security appliance software	View
129	cisco	adaptive security appliance software	View
130	cisco	adaptive security appliance software	View
131	cisco	adaptive security appliance software	View
132	cisco	adaptive security appliance software	View
133	cisco	adaptive security appliance software	View
134	cisco	adaptive security appliance software	View
135	cisco	adaptive security appliance software	View
136	cisco	secure firewall threat defense	View
137	cisco	secure firewall threat defense	View
138	cisco	secure firewall threat defense	View
139	cisco	secure firewall threat defense	View
140	cisco	secure firewall threat defense	View
141	cisco	secure firewall threat defense	View
142	cisco	secure firewall threat defense	View
143	cisco	secure firewall threat defense	View
144	cisco	secure firewall threat defense	View
145	cisco	secure firewall threat defense	View
146	cisco	secure firewall threat defense	View
147	cisco	secure firewall threat defense	View
148	cisco	secure firewall threat defense	View
149	cisco	secure firewall threat defense	View
150	cisco	secure firewall threat defense	View
151	cisco	secure firewall threat defense	View
152	cisco	secure firewall threat defense	View
153	cisco	secure firewall threat defense	View
154	cisco	secure firewall threat defense	View
155	cisco	secure firewall threat defense	View
156	cisco	secure firewall threat defense	View
157	cisco	secure firewall threat defense	View
158	cisco	secure firewall threat defense	View
159	cisco	secure firewall threat defense	View
160	cisco	secure firewall threat defense	View
161	cisco	secure firewall threat defense	View
162	cisco	secure firewall threat defense	View
163	cisco	secure firewall threat defense	View
164	cisco	secure firewall threat defense	View
165	cisco	secure firewall threat defense	View
166	cisco	secure firewall threat defense	View
167	cisco	secure firewall threat defense	View
168	cisco	secure firewall threat defense	View
169	cisco	secure firewall threat defense	View
170	cisco	secure firewall threat defense	View
171	cisco	secure firewall threat defense	View
172	cisco	secure firewall threat defense	View
173	cisco	secure firewall threat defense	View
174	cisco	secure firewall threat defense	View
175	cisco	secure firewall threat defense	View
176	cisco	secure firewall threat defense	View
177	cisco	secure firewall threat defense	View
178	cisco	secure firewall threat defense	View
179	cisco	secure firewall threat defense	View
180	cisco	secure firewall threat defense	View
181	cisco	secure firewall threat defense	View
182	cisco	secure firewall threat defense	View
183	cisco	secure firewall threat defense	View
184	cisco	secure firewall threat defense	View
185	cisco	secure firewall threat defense	View
186	cisco	secure firewall threat defense	View
187	cisco	secure firewall threat defense	View
188	cisco	secure firewall threat defense	View
189	cisco	secure firewall threat defense	View
190	cisco	secure firewall threat defense	View
191	cisco	secure firewall threat defense	View
192	cisco	secure firewall threat defense	View
193	cisco	secure firewall threat defense	View
194	cisco	secure firewall threat defense	View
195	cisco	secure firewall threat defense	View
196	cisco	secure firewall threat defense	View
197	cisco	secure firewall threat defense	View
198	cisco	secure firewall threat defense	View
199	cisco	secure firewall threat defense	View
200	cisco	Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD)	View

Total affected vendors: 1|Products: 200

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCORE	VERSION	SEVERITY	VECTOR	SOURCE
8.6	CVSS V3_1	HIGH	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H	CVE CNA
8.6	CVSS V31	HIGH	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H	NVD

Patch and Remediation Guide

Solution & Remediation Advisory

Workaround

Resmî yama doğrulanamadı; geçici azaltım veya workaround mevcut.

canonical

Confirm the affected product and version against the source evidence above.

Restrict access to internet-facing services and apply network segmentation.

Until a patch is confirmed, follow the vendor advisory; do not read an unknown status as “no patch”.

Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

This CVE is marked as actively exploited in the CISA KEV catalogue, but no verified, downloadable public PoC or Metasploit module has been found yet. Evidence of active exploitation does not mean that public exploit code exists.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-20349 is associated with the following CWEs:

CWE-244: Common Weakness Enumeration Entry CWE-244

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-20349 weaknesses.

CAPEC-66: SQL Injection CAPEC-126: Path Traversal CAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureAğ üzerinden

PermissionsGerekmiyor

UserGerekmiyor

Official Sources and Advisories

cisco-sa-asaftd-vpn-dos-dzv4mQFFvendor-advisory https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20349nvd CISA Known Exploited Vulnerabilities Catalogkev

CVSS Vector Radar Chart

8.6 / 10

Vulnerability Scoring Details

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

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone required

User InteractionNone required

Confidentiality (Gizlilik)Low

Integrity (Bütünlük)None

Availability (Erişilebilirlik)High

Geçici çözüm

Resmî yama doğrulanamadı; geçici azaltım veya workaround mevcut.

Follow the vendor

cisco

Weakness Type (CWE & CAPEC)

CWE-244

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Get this vulnerability through the API

Affected products, version ranges, exploitation status and patch information in a single request, with a free key.

Get a free key Documentation

curl -H "x-api-key: $DAYBREACH_API_KEY" \
  "https://api.enginteksut.com.tr/api/v1/intel/cves/CVE-2026-20349"