CVE-2018-6918: Freebsd

High severity, CVSS 7.5. EPSS: 4.2% chance of exploitation in the next 30 days.

In FreeBSD before 11.1-STABLE, 11.1-RELEASE-p9, 10.4-STABLE, 10.4-RELEASE-p8 and 10.3-RELEASE-p28, the length field of the ipsec option header does not count the size of the option header itself, causing an infinite loop when the length is zero. This issue can allow a remote attacker who is able to send an arbitrary packet to cause the machine to crash.

Affected products

• Freebsd Freebsd: from 10.0, before 10.4 (fixed in 10.4); from 11.0, before 11.1 (fixed in 11.1)

Published 2018-04-04. Last modified 2026-06-17.