Cisco ASA and FTD Information Disclosure Vulnerability
Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) contain an information disclosure vulnerability. An attacker could retrieve memory contents on an affected device, which could lead to the disclosure of confidential information due to a buffer tracking issue when the software parses invalid URLs that are requested from the web services interface. This vulnerability affects only specific AnyConnect and WebVPN configurations.
- Vendor
- Cisco
- Product
- Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD)
- CVSS
- 7.5
- EPSS (exploit probability)
- 71.5%
- Status
- kevransomware use
- CISA patch-by (BOD 22-01)
- Added to KEV
Is CVE-2020-3259 being exploited?
Yes. CISA added CVE-2020-3259 to its Known Exploited Vulnerabilities catalog on . CISA only lists a CVE when it has reliable evidence of exploitation in the wild. CISA marks it as known to be used in ransomware campaigns.
FIRST's EPSS model puts the probability of exploitation activity in the next 30 days at 71.5% (scored October 21, 2026).
- CISA KEV[ LISTED ]
- ENISA EUVD (exploited)[ — ]
- CIRCL KEV[ — ]
Catalog snapshot 2026-11-13. Full cross-catalog view: /kev-comparison
CVE-2020-3259 timeline
Every event links to its source. Catalog dates are each catalog's own; day offsets count from NVD publication. Data: JSON
What to do
CISA required actionApply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
US federal civilian agencies must remediate by (21 days after listing) under BOD 22-01. Everyone else: that deadline is a sensible upper bound, not a target. Vendor guidance and the NVD record are linked under Source above.
Other Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) CVEs we track
| CVE / Vulnerability | Severity | CVSS | EPSS | Added to KEV |
|---|---|---|---|---|
| CVE-2026-20349 Cisco ASA and FTD VPN Heap Inspection Denial-of-Service Flawwrite-up | [ HIGH ] | 8.6 | 1.0% | |
| CVE-2025-20362 Cisco Secure Firewall Adaptive Security (ASA) Appliance and Secure Firewall Threat Defense (FTD) Missing Authorization Vulnerability | [ MEDIUM ] | 6.5 | 86.7% | |
| CVE-2025-20333 Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Buffer Overflow Vulnerability | [ CRITICAL ] | 9.9 | 72.0% | |
| CVE-2024-20481 Cisco ASA and FTD Denial-of-Service Vulnerability | [ MEDIUM ] | 5.8 | 15.9% | |
| CVE-2024-20359 Cisco ASA and FTD Privilege Escalation Vulnerability | [ MEDIUM ] | 6.0 | 18.8% | |
| CVE-2024-20353 Cisco ASA and FTD Denial of Service Vulnerability | [ HIGH ] | 8.6 | 69.8% | |
| CVE-2023-20269 Cisco Adaptive Security Appliance and Firepower Threat Defense Unauthorized Access Vulnerabilityransomware use | [ MEDIUM ] | 5.0 | 26.6% | |
| CVE-2020-3580 Cisco ASA and FTD Cross-Site Scripting (XSS) Vulnerabilityransomware use | [ MEDIUM ] | 6.1 | 85.6% |