Openbsd: community verdicts

3 notable / known-exploited Openbsd CVEs the community has triaged.

ⓘ Not an exhaustive list: we focus on the findings that matter (exploited / notable). For every Openbsd CVE, see NVD ↗.

Exploitation first, with newly exploited CVEs rising above old ones

CVE-2020-7247CRIT 9.8KEVEPSS 99%
smtp_mailaddr in smtp_session.c in OpenSMTPD 6.6, as used in OpenBSD 6.6 and other products, allows remote attackers to execute arbitrary commands as root via a crafted SMTP session, as demonstrated by shell metacharacters in a MAIL FROM field. This affects the "uncommented" default configuration. The issue exists because of an incorrect return value upon failure of input validation.
CVE-2024-6387HIGH 8.1Likely realEPSS 100%
A security regression (CVE-2006-5051) was discovered in OpenSSH's server (sshd). There is a race condition which can lead sshd to handle some signals in an unsafe manner. An unauthenticated, remote attacker may be able to trigger it by failing to authenticate within a set time period.
CVE-2025-26466MED 5.9EPSS 41%
A flaw was found in the OpenSSH package. For each ping packet the SSH server receives, a pong packet is allocated in a memory buffer and stored in a queue of packages. It is only freed when the server/client key exchange has finished. A malicious client may keep sending such packages, leading to an uncontrolled increase in memory consumption on the server side. Consequently, the server may become unavailable, resulting in a denial of service attack.