CVE-2026-54906 concurrent-ruby: ReadWriteLock allows wrong-thread write release and stray read-release counter corruption

concurrent-ruby is a modern concurrency tools for Ruby. Prior to 1.3.7, Concurrent::ReadWriteLockreleasewritelock does not verify that the calling thread acquired the write lock. Any thread with access to the lock object can release an active write lock held by another thread. A second writer can...

CVE-2026-54906 concurrent-ruby: ReadWriteLock allows wrong-thread write release and stray read-release counter corruption

concurrent-ruby is a modern concurrency tools for Ruby. Prior to 1.3.7, Concurrent::ReadWriteLockreleasewritelock does not verify that the calling thread acquired the write lock. Any thread with access to the lock object can release an active write lock held by another thread. A second writer can...

Concurrent Ruby: ReadWriteLock allows wrong-thread write release and stray read-release counter corruption

Summary Concurrent::ReadWriteLockreleasewritelock does not verify that the calling thread acquired the write lock. Any thread with access to the lock object can release an active write lock held by another thread. A second writer can then enter its critical section while the first writer is still...