Buffer Access with Incorrect Length Value in Snort - CVE-2026-20011
Published: October 21, 2026
Vulnerability identifier: #VU156725
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-20011
CWE-ID: CWE-805
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service by triggering an unexpected restart of the Snort 3 Detection Engine.
The vulnerability exists due to a lack of error checking in the Snort 3 SMTP MIME Decoder when parsing MIME fields in SMTP headers. A remote attacker can send crafted SMTP packets through an established connection for inspection by Snort 3 to cause the detection engine to restart.
Exploitation on Cisco Secure FTD Software requires Snort 3 to be active.
Affected software
Snort
How to mitigate CVE-2026-20011
Install security update from vendor's website.
Snort - update to 3.10.1.0