What is CVE-2026-54905?

CVE-2026-54905 is a medium-severity vulnerability in Ruby-concurrency Concurrent-ruby, classified under Wrap-around Error. CVSS score: 5.5/10. Published 2026-06-24.

How severe is CVE-2026-54905?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Vulnerability in Ruby-concurrency Concurrent-ruby

CVE-2026-54905

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 w…

EPSS: 0.001 (1.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

Affected products

Ruby-concurrency Concurrent-ruby — versions < 1.3.7
Rubyconcurrency Concurrent_ruby

Weakness classification (CWE)

CWE-128 — Wrap-around Error

References

security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory)

Frequently asked questions

What is CVE-2026-54905?: CVE-2026-54905 is a medium-severity vulnerability in Ruby-concurrency Concurrent-ruby, classified under Wrap-around Error. CVSS score: 5.5/10. Published 2026-06-24.
How severe is CVE-2026-54905?: Medium severity. CVSS v3 base score is 5.5 out of 10.