6.5

CVE-2026-20023: cisco adaptive_security_appliance_software Out-of-bounds Write

Analyzed
Published 04-03-2026Last modified 04-03-2026

Vulnerability summary

CVE-2026-20023 is a medium (CVSS 6.5) Out-of-bounds Write vulnerability in cisco adaptive_security_appliance_software. EPSS estimates a 0.15% chance of exploitation in the next 30 days, higher than 3.9% of scored vulnerabilities.

Overall risk
26/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.15%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 04-03-2026
    PublishedVulnerability first disclosed.
  2. 04-03-2026
    Last modifiedVulnerability information updated.

Description

A vulnerability in the OSPF protocol of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, adjacent attacker to corrupt memory on an affected device, resulting in a denial of service (DoS) condition. This vulnerability is due to memory corruption when parsing OSPF protocol packets. An attacker could exploit this vulnerability by sending crafted OSPF packets to an affected device. A successful exploit could allow the attacker to cause memory corruption causing the affected device to reboot, resulting in a DoS condition.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.15%

Chance of exploitation in the next 30 days

Percentile

4%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.15% on 22-09-2026

22-09-202622-10-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Cisco4 products
  • adaptive_security_appliance_software9.12.1 | 9.12.1.2 | 9.12.1.3 | 9.12.2 | 9.12.2.1 | 9.12.2.4 | 9.12.2.5 | 9.12.2.9 | 9.12.3 | 9.12.3.2 | 9.12.3.7 | 9.12.3.9 | 9.12.3.12 | 9.12.4 | 9.12.4.2 | 9.12.4.4 | 9.12.4.7 | 9.12.4.8 | 9.12.4.10 | 9.12.4.13 | 9.12.4.18 | 9.12.4.24 | 9.12.4.26 | 9.12.4.29 | 9.12.4.30 | 9.12.4.35 | 9.12.4.37 | 9.12.4.38 | 9.12.4.39 | 9.12.4.40 | 9.12.4.41 | 9.12.4.47 | 9.12.4.48 | 9.12.4.50 | 9.12.4.52 | 9.12.4.54 | 9.12.4.55 | 9.12.4.56 | 9.12.4.58 | 9.12.4.62 | 9.12.4.65 | 9.12.4.67 | 9.16.1 | 9.16.1.28 | 9.16.2 | 9.16.2.3 | 9.16.2.7 | 9.16.2.11 | 9.16.2.13 | 9.16.2.14 | 9.16.3 | 9.16.3.3 | 9.16.3.14 | 9.16.3.15 | 9.16.3.19 | 9.16.3.23 | 9.16.4 | 9.16.4.9 | 9.16.4.14 | 9.16.4.19 | 9.16.4.27 | 9.16.4.38 | 9.16.4.39 | 9.16.4.42 | 9.16.4.48 | 9.16.4.55 | 9.16.4.57 | 9.16.4.61 | 9.16.4.62 | 9.16.4.67 | 9.16.4.70 | 9.16.4.71 | 9.16.4.76 | 9.16.4.82 | 9.16.4.84 | 9.16.4.85 | 9.17.1 | 9.17.1.7 | 9.17.1.9 | 9.17.1.10 | 9.17.1.11 | 9.17.1.13 | 9.17.1.15 | 9.17.1.20 | 9.17.1.30 | 9.17.1.33 | 9.17.1.39 | 9.17.1.45 | 9.17.1.46 | 9.18.1 | 9.18.1.3 | 9.18.2 | 9.18.2.5 | 9.18.2.7 | 9.18.2.8 | 9.18.3 | 9.18.3.39 | 9.18.3.46 | 9.18.3.53 | 9.18.3.55 | 9.18.3.56 | 9.18.4 | 9.18.4.5 | 9.18.4.8 | 9.18.4.22 | 9.18.4.24 | 9.18.4.29 | 9.18.4.34 | 9.18.4.40 | 9.18.4.47 | 9.18.4.50 | 9.18.4.52 | 9.18.4.53 | 9.18.4.57 | 9.18.4.66 | 9.18.4.67 | 9.18.4.68 | 9.19.1 | 9.19.1.5 | 9.19.1.9 | 9.19.1.12 | 9.19.1.18 | 9.19.1.22 | 9.19.1.24 | 9.19.1.27 | 9.19.1.28 | 9.19.1.31 | 9.19.1.37 | 9.19.1.38 | 9.19.1.42 | 9.20.1 | 9.20.1.5 | 9.20.2 | 9.20.2.10 | 9.20.2.21 | 9.20.2.22 | 9.20.3 | 9.20.3.4 | 9.20.3.7 | 9.20.3.9 | 9.20.3.10 | 9.20.3.13 | 9.20.3.16 | 9.20.4 | 9.20.4.7 | 9.20.4.10 | 9.20.4.14 | 9.22.1.1 | 9.22.1.2 | 9.22.1.3 | 9.22.1.6 | 9.22.2.9 | 9.22.2.13 | 9.22.2.14 | 9.23.1 | 9.23.1.7 | 9.23.1.13 | 9.23.1.19 | 9.23.1.22
  • cisco secure firewall adaptive security appliance (asa) software9.12.1 | 9.12.1.2 | 9.12.1.3 | 9.12.2 | 9.12.2.4 | 9.12.2.5 | 9.12.2.9 | 9.12.3 | 9.12.3.2 | 9.12.3.7 | 9.12.4 | 9.12.3.12 | 9.12.3.9 | 9.12.2.1 | 9.12.4.2 | 9.12.4.4 | 9.12.4.7 | 9.12.4.10 | 9.12.4.13 | 9.12.4.8 | 9.12.4.18 | 9.12.4.24 | 9.12.4.26 | 9.12.4.29 | 9.12.4.30 | 9.12.4.35 | 9.12.4.37 | 9.12.4.38 | 9.12.4.39 | 9.12.4.40 | 9.12.4.41 | 9.12.4.47 | 9.12.4.48 | 9.12.4.50 | 9.12.4.52 | 9.12.4.54 | 9.12.4.55 | 9.12.4.56 | 9.12.4.58 | 9.12.4.62 | 9.12.4.65 | 9.12.4.67 | 9.16.1 | 9.16.1.28 | 9.16.2 | 9.16.2.3 | 9.16.2.7 | 9.16.2.11 | 9.16.2.13 | 9.16.2.14 | 9.16.3 | 9.16.3.3 | 9.16.3.14 | 9.16.3.15 | 9.16.3.19 | 9.16.3.23 | 9.16.4 | 9.16.4.9 | 9.16.4.14 | 9.16.4.19 | 9.16.4.27 | 9.16.4.38 | 9.16.4.39 | 9.16.4.42 | 9.16.4.48 | 9.16.4.55 | 9.16.4.57 | 9.16.4.61 | 9.16.4.62 | 9.16.4.67 | 9.16.4.70 | 9.16.4.71 | 9.16.4.76 | 9.16.4.82 | 9.16.4.84 | 9.16.4.85 | 9.17.1 | 9.17.1.7 | 9.17.1.9 | 9.17.1.10 | 9.17.1.11 | 9.17.1.13 | 9.17.1.15 | 9.17.1.20 | 9.17.1.30 | 9.17.1.33 | 9.17.1.39 | 9.17.1.45 | 9.17.1.46 | 9.18.1 | 9.18.1.3 | 9.18.2 | 9.18.2.5 | 9.18.2.7 | 9.18.2.8 | 9.18.3 | 9.18.3.39 | 9.18.3.46 | 9.18.3.53 | 9.18.3.55 | 9.18.3.56 | 9.18.4 | 9.18.4.5 | 9.18.4.8 | 9.18.4.22 | 9.18.4.24 | 9.18.4.29 | 9.18.4.34 | 9.18.4.40 | 9.18.4.47 | 9.18.4.50 | 9.18.4.52 | 9.18.4.53 | 9.18.4.57 | 9.18.4.66 | 9.18.4.67 | 9.18.4.68 | 9.19.1 | 9.19.1.5 | 9.19.1.9 | 9.19.1.12 | 9.19.1.18 | 9.19.1.22 | 9.19.1.24 | 9.19.1.27 | 9.19.1.28 | 9.19.1.31 | 9.19.1.37 | 9.19.1.38 | 9.19.1.42 | 9.20.1 | 9.20.1.5 | 9.20.2 | 9.20.2.10 | 9.20.2.21 | 9.20.2.22 | 9.20.3 | 9.20.3.4 | 9.20.3.7 | 9.20.3.9 | 9.20.3.10 | 9.20.3.13 | 9.20.3.16 | 9.20.4 | 9.20.4.7 | 9.20.4.10 | 9.20.4.14 | 9.22.1.1 | 9.22.1.3 | 9.22.1.2 | 9.22.1.6 | 9.22.2.9 | 9.22.2.13 | 9.22.2.14 | 9.23.1 | 9.23.1.7 | 9.23.1.13 | 9.23.1.19 | 9.23.1.22
  • cisco secure firewall threat defense (ftd) software6.4.0 | 6.4.0.1 | 6.4.0.3 | 6.4.0.2 | 6.4.0.4 | 6.4.0.5 | 6.4.0.6 | 6.4.0.7 | 6.4.0.8 | 6.4.0.9 | 6.4.0.10 | 6.4.0.11 | 6.4.0.12 | 6.4.0.13 | 6.4.0.14 | 6.4.0.15 | 6.4.0.16 | 6.4.0.17 | 6.4.0.18 | 7.0.0 | 7.0.0.1 | 7.0.1 | 7.0.1.1 | 7.0.2 | 7.0.2.1 | 7.0.3 | 7.0.4 | 7.0.5 | 7.0.6 | 7.0.6.1 | 7.0.6.2 | 7.0.6.3 | 7.0.7 | 7.0.8 | 7.0.8.1 | 7.1.0 | 7.1.0.1 | 7.1.0.2 | 7.1.0.3 | 7.2.0 | 7.2.0.1 | 7.2.1 | 7.2.2 | 7.2.3 | 7.2.4 | 7.2.4.1 | 7.2.5 | 7.2.5.1 | 7.2.6 | 7.2.7 | 7.2.5.2 | 7.2.8 | 7.2.8.1 | 7.2.9 | 7.2.10 | 7.2.10.2 | 7.3.0 | 7.3.1 | 7.3.1.1 | 7.3.1.2 | 7.4.0 | 7.4.1 | 7.4.1.1 | 7.4.2 | 7.4.2.1 | 7.4.2.2 | 7.4.2.3 | 7.4.2.4 | 7.4.3 | 7.6.0 | 7.6.1 | 7.6.2 | 7.6.2.1 | 7.7.0 | 7.7.10.1
  • secure_firewall_threat_defense6.4.0 | 6.4.0.1 | 6.4.0.2 | 6.4.0.3 | 6.4.0.4 | 6.4.0.5 | 6.4.0.6 | 6.4.0.7 | 6.4.0.8 | 6.4.0.9 | 6.4.0.10 | 6.4.0.11 | 6.4.0.12 | 6.4.0.13 | 6.4.0.14 | 6.4.0.15 | 6.4.0.16 | 6.4.0.17 | 6.4.0.18 | 7.0.0 | 7.0.0.1 | 7.0.1 | 7.0.1.1 | 7.0.2 | 7.0.2.1 | 7.0.3 | 7.0.4 | 7.0.5 | 7.0.6 | 7.0.6.1 | 7.0.6.2 | 7.0.6.3 | 7.0.7 | 7.0.8 | 7.0.8.1 | 7.1.0 | 7.1.0.1 | 7.1.0.2 | 7.1.0.3 | 7.2.0 | 7.2.0.1 | 7.2.1 | 7.2.2 | 7.2.3 | 7.2.4 | 7.2.4.1 | 7.2.5 | 7.2.5.1 | 7.2.5.2 | 7.2.6 | 7.2.7 | 7.2.8 | 7.2.8.1 | 7.2.9 | 7.2.10 | 7.2.10.2 | 7.3.0 | 7.3.1 | 7.3.1.1 | 7.3.1.2 | 7.4.0 | 7.4.1 | 7.4.1.1 | 7.4.2 | 7.4.2.1 | 7.4.2.2 | 7.4.2.3 | 7.4.2.4 | 7.4.3 | 7.6.0 | 7.6.1 | 7.6.2 | 7.6.2.1 | 7.7.0 | 7.7.10.1

1 vendor · 4 products

References

1 links