CVE-2026-20291: Cisco Snort 3 improper privilege management

CVE-2026-20291 · Severity: high · CVSS 7.8 · Published 2026-10-21

Snort 3 is an open-source intrusion detection and prevention system used across multiple Cisco security products to inspect and block malicious network traffic. A privilege management flaw (CVE-2026-20291) allows an attacker with network access to gain elevated control or bypass security restrictions. This could compromise the security posture of firewalls and threat detection appliances that rely on Snort 3.

Technologies: Cisco Cloud-delivered Firewall, Cisco Cyber Vision, Cisco IOS XE Unified Threat Defense, Cisco Meraki MX Security Appliances, Cisco Secure Access, Cisco Secure Firewall Threat Defense, Cisco Snort 3. Vendors: Cisco.

Quick answers

Is CVE-2026-20291 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-20291 being exploited in the wild.
How severe is CVE-2026-20291?
High severity, with a CVSS score of 7.8, published 21 October 2026.
Which products and versions are affected?
Cisco Cloud-delivered Firewall all versions as of 2026-10-21; Cisco Cyber Vision before 5.6.0; Cisco IOS XE Unified Threat Defense all affected versions; Cisco Meraki MX Security Appliances all affected versions; and 3 more.
Is there a fix for CVE-2026-20291?
Yes: fixed in Snort 3 3.12.4.0; Cyber Vision 5.6.0; CDFW and CSA automatically updated as of 2026-10-21. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-20291 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-20291?
Check whether you run Cisco Cloud-delivered Firewall, Cisco Cyber Vision, Cisco IOS XE Unified Threat Defense or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • Fixed in: Snort 3 3.12.4.0; Cyber Vision 5.6.0; CDFW and CSA automatically updated as of 2026-10-21

Technical details

CVE-2026-20291 represents improper privilege management (CWE-269) in Snort 3 identified during Cisco's internal security review. The vulnerability requires network access and has a CVSS score of 7.8; the grouped advisory addresses multiple CWEs with a maximum CVSS of 9.0 across related hardening issues. Cisco has released patched versions and states no workarounds exist.

Affected products

  • Cisco Snort 3 3.x before 3.12.4.0
  • Cisco Cloud-delivered Firewall all versions as of 2026-10-21
  • Cisco Cyber Vision before 5.6.0
  • Cisco Meraki MX Security Appliances all affected versions
  • Cisco Secure Access all versions as of 2026-10-21
  • Cisco Secure Firewall Threat Defense all affected versions
  • Cisco IOS XE Unified Threat Defense all affected versions

Timeline

  • 2026-10-21: disclosed: CVE-2026-20291 published

References

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