CVE-2026-54905

A flaw was found in concurrent-ruby. The Concurrent::ReentrantReadWriteLock component can incorrectly grant a write lock to a thread while other threads still hold or can acquire read locks. This occurs when a thread acquires a read lock 32,768 times, causing an internal counter to incorrectly...

CVE-2026-54906

A flaw was found in concurrent-ruby, a Ruby library for managing concurrent operations. The Concurrent::ReadWriteLock component contains a synchronization issue where write locks can be released by unauthorized threads. This could allow multiple threads to write concurrently, potentially leading ...

Linux Distros Unpatched Vulnerability : CVE-2026-54906

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - concurrent-ruby is a modern concurrency tools for Ruby. Prior to 1.3.7, Concurrent::ReadWriteLockreleasewritelock does not verify that the calling thread acquir...

Linux Distros Unpatched Vulnerability : CVE-2026-54905

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - concurrent-ruby is a modern concurrency tools for Ruby. Prior to 1.3.7, Concurrent::ReentrantReadWriteLock can incorrectly grant a write lock after one thread...

CVE-2026-54906

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-2026-54905

concurrent-ruby is a modern concurrency tools for Ruby. Prior to 1.3.7, Concurrent::ReentrantReadWriteLock can incorrectly grant a write lock after one thread acquires the read lock 32,768 times. The lock stores a thread's local read and write hold counts in one integer. The low 15 bits are used...

EUVD-2026-38941

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hcildisc: Clear HCIUARTPROTOINIT on error When hciregisterdev fails in hciuartregisterdev HCIUARTPROTOINIT is not cleared before calling hu-proto-closehu and setting hu-hdev to NULL. This means incoming UART data will...

CVE-2026-54906

Vulnerability summary (CVE-2026-54906) : In the Ruby concurrency library concurrent-ruby (ReadWriteLock), versions prior to 1.3.7 expose a synchronization bug in the public API. Specifically, release_write_lock does not verify that the calling thread owns the write lock, allowing another thread t...

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-2026-54905

CVE-2026-54905 affects the concurrent-ruby library, specifically Concurrent::ReentrantReadWriteLock. Before version 1.3.7, after a thread acquires the read lock 32,768 times, the local read count overflows into the WRITE_LOCK_HELD bit, causing try_write_lock to treat the thread as if it holds a w...

CVE-2026-54905 concurrent-ruby: `ReentrantReadWriteLock` read-count overflow grants a write lock without exclusivity

concurrent-ruby is a modern concurrency tools for Ruby. Prior to 1.3.7, Concurrent::ReentrantReadWriteLock can incorrectly grant a write lock after one thread acquires the read lock 32,768 times. The lock stores a thread's local read and write hold counts in one integer. The low 15 bits are used...

GHSA-6WX8-W4F5-WWCR 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...

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...

Improper Locking

Overview Affected versions of this package are vulnerable to Improper Locking in the releasewritelock and releasereadlock functions. An attacker can disrupt synchronization guarantees and exploit data races or cause denial of service by invoking these functions from unauthorized threads or withou...

GHSA-WV3X-4VXV-WHPP Concurrent Ruby: `ReentrantReadWriteLock` read-count overflow grants a write lock without exclusivity

Summary Concurrent::ReentrantReadWriteLock can incorrectly grant a write lock after one thread acquires the read lock 32,768 times. The lock stores a thread's local read and write hold counts in one integer. The low 15 bits are used for the read hold count, and bit 15 is used as WRITELOCKHELD...

Concurrent Ruby: `ReentrantReadWriteLock` read-count overflow grants a write lock without exclusivity

Summary Concurrent::ReentrantReadWriteLock can incorrectly grant a write lock after one thread acquires the read lock 32,768 times. The lock stores a thread's local read and write hold counts in one integer. The low 15 bits are used for the read hold count, and bit 15 is used as WRITELOCKHELD...

PT-2026-51092

Name of the Vulnerable Software and Affected Versions concurrent-ruby versions prior to 1.3.7 Description A synchronization correctness issue exists in the public Concurrent::ReadWriteLock API. The function release write lock does not verify if the calling thread actually acquired the write lock,...

PT-2026-51091

Name of the Vulnerable Software and Affected Versions concurrent-ruby versions prior to 1.3.7 Description Concurrent::ReentrantReadWriteLock can incorrectly grant a write lock after a single thread acquires the read lock 32,768 times. The lock manages a thread's local read and write hold counts...

Concurrent Ruby - `ReentrantReadWriteLock` read-count overflow grants a write lock without exclusivity

Summary Concurrent::ReentrantReadWriteLock can incorrectly grant a write lock after one thread acquires the read lock 32,768 times. The lock stores a thread's local read and write hold counts in one integer. The low 15 bits are used for the read hold count, and bit 15 is used as WRITELOCKHELD...

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...