Wrap-around Error Affecting ruby-concurrent package, versions *


Severity

Recommended
low

Based on Debian security rating.

Threat Intelligence

EPSS
0.15% (5th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-DEBIAN12-RUBYCONCURRENT-17446580
  • published25 Jun 2026
  • disclosed24 Jun 2026

Introduced: 24 Jun 2026

CVE-2026-54905  (opens in a new tab)
CWE-128  (opens in a new tab)

How to fix?

There is no fixed version for Debian:12 ruby-concurrent.

NVD Description

Note: Versions mentioned in the description apply only to the upstream ruby-concurrent package and not the ruby-concurrent package as distributed by Debian. See How to fix? for Debian:12 relevant fixed versions and status.

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 for the read hold count, and bit 15 is used as WRITE_LOCK_HELD. After 32,768 reentrant read acquisitions, the local read count crosses into the write-lock bit. try_write_lock then treats the thread as already holding a write lock and returns true without setting the global RUNNING_WRITER bit. This breaks the core mutual-exclusion guarantee: the caller is told it has a write lock, but other threads can still hold or acquire read locks at the same time. This vulnerability is fixed in 1.3.7.

CVSS Base Scores

version 3.1