How severe is CVE-2026-20067?

CVE-2026-20067 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-2026-20067 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-20067?

CVE-2026-20067 primarily affects Cisco Snort. In total, 182 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-20067?

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

Does CVE-2026-20067 have an EU (EUVD) identifier?

Yes. CVE-2026-20067 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9466.

When was CVE-2026-20067 published?

CVE-2026-20067 was published on 2026-03-04 and last updated on 2026-08-19.

CVE-2026-20067

CVE-2026-20067 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-787.

Key facts

Severity: Medium (CVSS 3.x base score 5.8)
EPSS exploit prediction: 0% (39th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-9466
Weakness: CWE-787
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 incomplete error checking when parsing the Multicast DNS fields of the HTTP header. An attacker could exploit this vulnerability by sending crafted HTTP packets through an established connection to be parsed by Snort 3. A successful exploit could allow the attacker to cause a DoS condition when the Snort 3 Detection Engine unexpectedly restarts.

Frequently asked questions

What is CVE-2026-20067?: 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 incomplete error checking when parsing the Multicast DNS fields of the HTTP header. An attacker could exploit this vulnerability by sending crafted HTTP packets through an established connection to be parsed by Snort 3. A successful exploit could allow the attacker to cause a DoS condition when the Snort 3 Detection Engine unexpectedly restarts.
How severe is CVE-2026-20067?: CVE-2026-20067 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-2026-20067 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-20067?: CVE-2026-20067 primarily affects Cisco Snort. In total, 182 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-20067?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-20067 have an EU (EUVD) identifier?: Yes. CVE-2026-20067 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9466.
When was CVE-2026-20067 published?: CVE-2026-20067 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 (182)

cpe:2.3:a:cisco:snort:*:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:3.0.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:3.0.1:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:3.0.2:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:3.0.3:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:3.0.4:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:3.0.5:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:3.0.6:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:3.1.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:3.1.1:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:3.1.2:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:3.2.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:3.2.1:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:3.2.2:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:3.2.3:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:3.2.4:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.0.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.0.1:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.0.2:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.0.3:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.1.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.1.1:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.1.2:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.1.3:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.1.4:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.1.5:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.1.6:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.1.7:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.2.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.2.1:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.2.2:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.2.3:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.2.4:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.2.6:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.3.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.3.1:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.3.2:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.3.3:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.4.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cyber_vision:4.4.1:*:*:*:*:*:*:*

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