CVE-2026-54906— concurrent-ruby: ReadWriteLock allows wrong-thread write release and stray read-release counter corruption
Quick assessment
Affected
ruby-concurrency concurrent-ruby
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
ruby-concurrency Concurrent Ruby是ruby-concurrency组织开源的一款并发编程工具库。 ruby-concurrency Concurrent Ruby 1.3.7之前版本存在资源管理错误漏洞，该漏洞源于同步正确性问题，具体体现在Concurrent::ReadWriteLock#release_write_lock未验证调用线程是否获取了写锁，以及Concurrent::ReadWriteLock#release_read_lock在未持有读锁时仍然递减共享计数
Possible ATT&CK Techniques 2 AI
T1068 · Exploitation for Privilege Escalation T1055 · Process InjectionAffected Version Matrix 1
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| ruby-concurrency | concurrent-ruby | < 1.3.7 |
affected |
Get alerts for future matching vulnerabilities
Log in to subscribe
I. Basic Information for CVE-2026-54906
Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗
Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.
Vulnerability Title
concurrent-ruby: ReadWriteLock allows wrong-thread write release and stray read-release counter corruption
Source: CVE Program / CVE List V5
Vulnerability Description
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.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:4.0/AV:L/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
Source: CVE Program / CVE List V5
Vulnerability Type
加锁检查缺失
Source: CVE Program / CVE List V5
Vulnerability Title
ruby-concurrency Concurrent Ruby 资源管理错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
ruby-concurrency Concurrent Ruby是ruby-concurrency组织开源的一款并发编程工具库。 ruby-concurrency Concurrent Ruby 1.3.7之前版本存在资源管理错误漏洞，该漏洞源于同步正确性问题，具体体现在Concurrent::ReadWriteLock#release_write_lock未验证调用线程是否获取了写锁，以及Concurrent::ReadWriteLock#release_read_lock在未持有读锁时仍然递减共享计数
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
| Vendor | Product | Affected Versions | CPE | Subscribe |
|---|---|---|---|---|
| ruby-concurrency | concurrent-ruby | < 1.3.7 | - |
|
II. Public POCs for CVE-2026-54906
| # | POC Description | Source Link | Shenlong Link |
|---|
AI-Generated POC
Premium
No public POC found.
Login to generate AI POCIII. Intelligence Information for CVE-2026-54906
请登录查看更多情报信息。
Vendor Advisories for CVE-2026-54906 (1)
Same Patch Batch · ruby-concurrency · 2026-06-24 · 3 CVEs total
| CVE-2026-54904 | 8.2 HIGH | concurrent-ruby: `AtomicReference#update` livelocks when the stored value is `Float::NAN` |
| CVE-2026-54905 | concurrent-ruby: `ReentrantReadWriteLock` read-count overflow grants a write lock without |
IV. Related Vulnerabilities
V. Comments for CVE-2026-54906
No comments yet