CVE-2026-20065

CVE-2026-20065 is a medium-severity vulnerability in Cisco Snort with a CVSS 3.x base score of 5.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-667.

Key facts

• Severity: Medium (CVSS 3.x base score 5.8)
• EPSS exploit prediction: 0% (30th percentile)
• Actively exploited: Not listed in CISA KEV
• EU (EUVD) id: EUVD-2026-9464
• Weakness: CWE-667
• Affected product: Cisco Snort
• Published: 2026-03-04
• Last modified: 2026-08-19

Description

Multiple Cisco products are affected by a vulnerability in the Snort 3 Detection Engine that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, resulting in an interruption of packet inspection. This vulnerability is due to an error in the binder module initialization logic of the Snort Detection Engine. An attacker could exploit this vulnerability by sending certain packets through an established connection that is parsed by Snort 3. A successful exploit could allow the attacker to cause a DoS condition when the Snort 3 Detection Engine restarts unexpectedly.

Frequently asked questions

What is CVE-2026-20065?

Multiple Cisco products are affected by a vulnerability in the Snort 3 Detection Engine that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, resulting in an interruption of packet inspection. This vulnerability is due to an error in the binder module initialization logic of the Snort Detection Engine. An attacker could exploit this vulnerability by sending certain packets through an established connection that is parsed by Snort 3. A successful exploit could allow the attacker to cause a DoS condition when the Snort 3 Detection Engine restarts unexpectedly.

How severe is CVE-2026-20065?

CVE-2026-20065 has a CVSS 3.x base score of 5.8, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2026-20065 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-20065?

CVE-2026-20065 primarily affects Cisco Snort. In total, 122 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-20065?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-20065 have an EU (EUVD) identifier?

Yes. CVE-2026-20065 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9464.

When was CVE-2026-20065 published?

CVE-2026-20065 was published on 2026-03-04 and last updated on 2026-08-19.

References

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort3-multi-dos-XFWkWSwz

Affected products (122)

• cpe:2.3:a:cisco:snort:*:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.0:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.1.1:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.2:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.2.1:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.3:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.4:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.5:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.6:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.6.1:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.6.2:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.6.3:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.7:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.8:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.8.1:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0.2:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0.3:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.0:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.1:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.2:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.3:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.4:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.4.1:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.5:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.5.1:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.5.2:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.6:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.7:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.8:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.8.1:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.9:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.10:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.10.2:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.3.0:*:*:*:*:*:*:*
• cpe:2.3:a:cisco:secure_firewall_threat_defense:7.3.1:*:*:*:*:*:*:*

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