{"items":[{"id":"NVI-00015218","kind":"vulnerability","title":"Concurrent Ruby : `AtomicReference#update` livelocks when the stored value is `Float::NAN`","revision":2,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected.","NVD lastModified does not establish freshness of every associated CPE record."],"lifecycle":"active","identifiers":["GHSA-h8w8-99g7-qmvj","CVE-2026-54904"],"plain_summary":"GitHub lists this reviewed advisory for concurrent-ruby. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-4bfa2684eeb18f51212f117045281819"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-08-05T17:36:07.000Z","value":"7.5 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-42a93fa87724938e285b3a82eb2d2f19"},{"kind":"CVSS","as_of":"2026-10-25T22:10:00.150Z","value":"7.5 HIGH (3.1)","meaning":"nvd@nist.gov severity; no combined Null risk score.","source_id":"sr-4bfa2684eeb18f51212f117045281819"},{"kind":"CVSS","as_of":"2026-10-25T22:10:00.150Z","value":"8.2 HIGH (4.0)","meaning":"security-advisories@github.com severity; no combined Null risk score.","source_id":"sr-4bfa2684eeb18f51212f117045281819"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-42a93fa87724938e285b3a82eb2d2f19","url":"https://github.com/advisories/GHSA-h8w8-99g7-qmvj","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-h8w8-99g7-qmvj","publisher":"GitHub Advisory Database","observed_at":"2026-11-03T09:58:09.980Z"},{"id":"sr-4bfa2684eeb18f51212f117045281819","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-54904","basis":"official_catalog","notes":"This product uses data from the NVD API but is not endorsed or certified by the NVD.","title":"CVE-2026-54904","publisher":"NIST National Vulnerability Database","observed_at":"2026-11-08T01:48:19.229Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-42a93fa87724938e285b3a82eb2d2f19"],"technology":"concurrent-ruby","known_exclusions":[],"conditions_summary":"### Summary\n`Concurrent::AtomicReference#update` can enter a permanent busy retry loop when the current value is `Float::NAN`.\n\nThe issue is caused by the interaction between:\n- `AtomicReference#update`, which retries until `compare_and_set(old_value, new_value)` succeeds.\n- Numeric `compare_and_set`, which checks `old == old_value` before attempting the underlying atomic swap.\n- Ruby NaN semantics, where `Float::NAN == Float::NAN` is always `false`.\n\nAs a result, once an `AtomicReference` contains `Float::NAN`, calling `#update` repeatedly evaluates the caller's 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.\n\n### Version\nSoftware: concurrent-ruby\nVersion: 1.3.6\nCommit: 7a1b78941c081106c20a9ca0144ac73a48d254ab\n### Details\n\n`AtomicReference#update` retries until `compare_and_set` returns true:\n\n```ruby\ndef update\n  true until compare_and_set(old_value = get, new_value = yield(old_value))\n  new_value\nend\n```\n\nFor numeric expected values, `compare_and_set` uses numeric equality before attempting the underlying atomic compare-and-set:\n\n```ruby\ndef compare_and_set(ol","public_affected_ranges":["< 1.3.7"]}],"null_published_at":"2026-11-08T19:53:44.055Z","source_updated_at":"2026-08-05T17:36:07.000Z","source_disclosed_at":"2026-06-19T20:47:35.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Source facts changed; compare the preserved prior revision.","null_first_observed_at":"2026-11-03T09:58:09.980Z"},{"id":"NVI-00015218","kind":"vulnerability","title":"Concurrent Ruby : `AtomicReference#update` livelocks when the stored value is `Float::NAN`","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-h8w8-99g7-qmvj","CVE-2026-54904"],"plain_summary":"GitHub lists this reviewed advisory for concurrent-ruby. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-42a93fa87724938e285b3a82eb2d2f19"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-08-05T17:36:07.000Z","value":"7.5 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-42a93fa87724938e285b3a82eb2d2f19"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-42a93fa87724938e285b3a82eb2d2f19","url":"https://github.com/advisories/GHSA-h8w8-99g7-qmvj","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-h8w8-99g7-qmvj","publisher":"GitHub Advisory Database","observed_at":"2026-11-03T09:58:09.980Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-42a93fa87724938e285b3a82eb2d2f19"],"technology":"concurrent-ruby","known_exclusions":[],"conditions_summary":"### Summary\n`Concurrent::AtomicReference#update` can enter a permanent busy retry loop when the current value is `Float::NAN`.\n\nThe issue is caused by the interaction between:\n- `AtomicReference#update`, which retries until `compare_and_set(old_value, new_value)` succeeds.\n- Numeric `compare_and_set`, which checks `old == old_value` before attempting the underlying atomic swap.\n- Ruby NaN semantics, where `Float::NAN == Float::NAN` is always `false`.\n\nAs a result, once an `AtomicReference` contains `Float::NAN`, calling `#update` repeatedly evaluates the caller's 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.\n\n### Version\nSoftware: concurrent-ruby\nVersion: 1.3.6\nCommit: 7a1b78941c081106c20a9ca0144ac73a48d254ab\n### Details\n\n`AtomicReference#update` retries until `compare_and_set` returns true:\n\n```ruby\ndef update\n  true until compare_and_set(old_value = get, new_value = yield(old_value))\n  new_value\nend\n```\n\nFor numeric expected values, `compare_and_set` uses numeric equality before attempting the underlying atomic compare-and-set:\n\n```ruby\ndef compare_and_set(ol","public_affected_ranges":["< 1.3.7"]}],"null_published_at":"2026-11-03T10:03:26.562Z","source_updated_at":"2026-08-05T17:36:07.000Z","source_disclosed_at":"2026-06-19T20:47:35.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-11-03T09:58:09.980Z"}],"next_cursor":null,"snapshot_revision":"42594"}