{
  "cveId": "CVE-2026-54904",
  "url": "https://patchblox.com/security/cve/CVE-2026-54904",
  "summary": "CVE-2026-54904 is fixed in ruby-concurrent on 1 platform by DEBIAN-CVE-2026-54904 (version 1.3.7-1), released July 3, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "ruby-concurrent: concurrent-ruby is a modern concurrency tools for Ruby",
  "description": "concurrent-ruby is a modern concurrency tools for Ruby. Prior to 1.3.7, Concurrent::AtomicReference#update can enter a permanent busy retry loop when the current value is Float::NAN. The issue is caused by the interaction between AtomicReference#update, which retries until compare_and_set(old_value, new_value) succeeds; Numeric compare_and_set, which checks old == old_value before attempting the underlying atomic swap.; and Ruby NaN semantics, where Float::NAN == Float::NAN is always false. As a result, once an AtomicReference contains Float::NAN, calling #update repeatedly evaluates the caller\u0027s block and never returns. In services that store externally derived numeric values in an AtomicReference, this can cause CPU exhaustion or permanent request/job hangs. This vulnerability is fixed in 1.3.7.",
  "published": "2026-06-24T17:17:29Z",
  "severity": "high",
  "cvss": 7.5,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
  "epss": 0.00673,
  "epssPercentile": 0.5235,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "ruby-concurrent",
      "release": "Debian 14",
      "fixedVersion": "1.3.7-1",
      "fix": "DEBIAN-CVE-2026-54904",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-54904",
      "released": "2026-07-03T14:54:39Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T06:59:42Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}