ruby-concurrency concurrent-ruby

• CVE-2026-54906 Low 2.1 concurrent-ruby: ReadWriteLock allows wrong-thread write release and stray read-release counter corruption 0.2%
• CVE-2026-54904 High 8.2 concurrent-ruby: `AtomicReference#update` livelocks when the stored value is `Float::NAN` 0.7%
• CVE-2026-54905 Low 2.0 concurrent-ruby: `ReentrantReadWriteLock` read-count overflow grants a write lock without exclusivity 0.2%