CVE-2026-54906

concurrent-ruby is a modern concurrency tools for Ruby. Prior to 1.3.7, Concurrent::ReadWriteLock#release_write_lock 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 running. Concurrent::ReadWriteLock#release_read_lock also decrements the shared counter even when no read lock is held. Calling it on a fresh lock changes the counter from 0 to -1, after which normal read acquisition raises Concurrent::ResourceLimitError. This is a synchronization correctness issue in the public Concurrent::ReadWriteLock API. This vulnerability is fixed in 1.3.7.

CVSS

No CVSS.

References

Link	Resource
https://github.com/ruby-concurrency/concurrent-ruby/security/advisories/GHSA-6wx8-w4f5-wwcr
https://github.com/ruby-concurrency/concurrent-ruby/security/advisories/GHSA-6wx8-w4f5-wwcr

Configurations

No configuration.

History

24 Jun 2026, 19:17

Type	Values Removed	Values Added
References	~~() https://github.com/ruby-concurrency/concurrent-ruby/security/advisories/GHSA-6wx8-w4f5-wwcr -~~	() https://github.com/ruby-concurrency/concurrent-ruby/security/advisories/GHSA-6wx8-w4f5-wwcr -

24 Jun 2026, 17:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-06-24 17:17

Updated : 2026-06-25 16:10

NVD link : CVE-2026-54906

Mitre link : CVE-2026-54906

CVE.ORG link : CVE-2026-54906

JSON object : View

Products Affected

No product.

CWE

CWE-414

Missing Lock Check

CWE-667

Improper Locking

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