CVE-2026-46727

Description

An issue was discovered in Ruby 4 before 4.0.5. A race condition leading to a use-after-free in the pthread-based getaddrinfo timeout handler (rb_getaddrinfo in ext/socket/raddrinfo.c) allows a remote attacker who can delay DNS responses near the user-specified timeout to crash a Ruby process that calls Addrinfo.getaddrinfo(..., timeout:) or Socket.tcp(..., resolv_timeout:). Memory-corruption-based exploitation is theoretically possible. The attack could, for example, be carried out through a crafted authoritative DNS server or recursive resolver.

How to fix CVE-2026-46727

To remediate CVE-2026-46727, upgrade the affected package to a fixed version below.

• —upgrade to 4.0.5 or later
• —upgrade to 4.0.5 or later

Is CVE-2026-46727 being exploited?

Low — EPSS is 0.2%, meaning exploitation activity has not been observed at scale.

Affected packages (2)

• >= 4.0.0, < 4.0.5
• >= 4.0.0, < 4.0.5

CVSS scores

References (3)

• WEBhackerone.com/reports/3607434
• WEBnvd.nist.gov/vuln/detail/CVE-2026-46727
• WEBwww.ruby-lang.org/en/news/2026/05/20/getaddrinfo-cve-2026-46727/