CVE-2026-20011Multiple Cisco Products Snort 3 SMTP MIME Denial of Service Vulnerability
Updated under an hour ago ()
Does this affect you?
It affects Cisco Open Source Snort3 and 2 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
Do this next
Free account, 1 product
Multiple Cisco products are affected by a vulnerability in the Snort 3 SMTP MIME Decoder that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart. This vulnerability is due to a lack of error checking when the MIME fields of the SMTP header are parsed. An attacker could exploit this vulnerability by sending crafted SMTP packets through an established connection to be parsed by Snort 3. A successful exploit could allow the attacker to cause a denial of service (DoS) condition when the Snort 3 Detection Engine unexpectedly restarts.
- CVSS
- 5.8 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
- Weakness (CWE)
- CWE-805
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- cisco
- NVD analysis
- Awaiting Analysis
- Record last updated
- Oct 21, 2026
- First seen by InfoSec Signals
- Oct 21, 2026
Affected products
Cisco Cisco Open Source Snort3 cisco:open_source_snort3 (from the name) | 3.1.2.0; 3.1.3.0; 3.1.4.0; 3.1.5.0; 3.1.6.0; 3.1.7.0; 3.1.8.0; 3.1.9.0; and 92 more ranges | CNA record |
Cisco Cisco Secure Firewall Threat Defense (FTD) Software cisco:secure_firewall_threat_defense_ftd_software (from the name) | 7.0.0; 7.0.0.1; 7.0.1; 7.0.1.1; 7.0.2; 7.2.0; 7.0.2.1; 7.0.3; and 51 more ranges | CNA record |
Cisco Cisco UTD SNORT IPS Engine Software cisco:utd_snort_ips_engine_software (from the name) | 3.17.1S; 16.12.3; Fuji-16.9.5; 16.12.4; 17.3.1a; 16.6.6; 16.12.2; Fuji-16.9.6; and 99 more ranges | CNA record |
References
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort3-mime-vulns-bkXjcKkt
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.