CVE-2026-46727: ruby-lang ruby Race Condition

Vulnerability summary

CVE-2026-46727 is a high (CVSS 8.1) Race Condition vulnerability in ruby-lang ruby. EPSS estimates a 0.49% chance of exploitation in the next 30 days, higher than 41% of scored vulnerabilities.

Timeline

1. 22-05-2026
   PublishedVulnerability first disclosed.
2. 22-05-2026
   Last modifiedVulnerability information updated.

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.

• CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.