Live › vulnerability › CVE-2026-20011
Go to dashboardSnort 3 in multiple Cisco products fails to check errors while parsing MIME fields in SMTP headers. A remote, unauthenticated attacker can send crafted SMTP traffic to make the Snort 3 Detection Engine restart, causing denial of service.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-23 21:57 UTC. All times on this page are UTC.
Affected products are Cisco products that ship Snort 3 with SMTP inspection enabled, as named in the Cisco advisory. Sources do not list the exact product or version set, so check the vendor advisory before deciding. Systems that do not run Snort 3 SMTP inspection are likely not affected.
No product ranges from the sources yet.
Unknown from the sources.
Unknown from the sources.
Each row is the first time that source carried this signal. The analyst’s rows are its own findings.
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.
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