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

Overview

Severity

Medium (CVSS 5.5)

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Exploit Status

Not Exploited

Patch Tuesday

2026-Jun

Released

2026-06-27

EPSS Score

0.11% (percentile: 1.3%)

Affected Products (1)

Other

• 21471-17084

Revision History

• 2026-06-27: Information published.