CVE-2026-54906: concurrent-ruby: ReadWriteLock allows wrong-thread write release and stray read-release counter corruption

Overview

Severity

Critical (CVSS 9.8)

CVSS Vector

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

Exploit Status

Not Exploited

Patch Tuesday

2026-Jun

Released

2026-06-27

EPSS Score

0.16% (percentile: 5.6%)

Affected Products (1)

Other

• 21471-17084

Revision History

• 2026-06-27: Information published.