SB20261021127 - Buffer Access with Incorrect Length Value in Snort

Description

This security bulletin contains information about 1 vulnerability.

1) Buffer Access with Incorrect Length Value (CVE-ID: CVE-2026-20011)

CWE-ID: CWE-805 - Buffer Access with Incorrect Length Value

CVSSv4: 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]

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.

Remediation

Install update from vendor's website.

References

• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort3-mime-vulns-bkXjcKkt
• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort3-mime-vulns-bkXjcKkt