Concurrent Ruby AtomicReference Heap Buffer Overflow DoS

The vulnerability of the update method in the Concurrent::AtomicReference class in the Ruby Concurrent library is related to the execution of a loop with an unreachable exit condition. Exploiting this vulnerability could allow a malicious actor to cause service failures...

CVE-2026-54904

concurrent-ruby is a modern concurrency tools for Ruby. Prior to 1.3.7, Concurrent::AtomicReferenceupdate can enter a permanent busy retry loop when the current value is Float::NAN. The issue is caused by the interaction between AtomicReferenceupdate, which retries until compareandsetoldvalue,...