CVE-2026-54904

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.7%, top 50% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Elevated
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.7%CVSS: 7.5Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

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'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. This vulnerability is fixed in 1.3.7.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
50
EG Risk 50/100

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity75% × 45%
Exploitation40% × 40%
Automatability0% × 15%
EPSS PROB
0.7%
EPSS %ILE
50th
KEV
Not listed

Published

June 19, 2026

Last Modified

August 5, 2026

Advisory Details (1)

Auto-updated Jun 24, 2026
🔬 Proof of concept available. Patch available. Sources: github.
githubMentions a patch (unverified)🟡 PoC Available

`AtomicReference#update` livelocks when the stored value is `Float::NAN` · Advisory · ruby-concurrency/concurrent-ruby · GitHub

https://github.com/ruby-concurrency/concurrent-ruby/security/advisories/GHSA-h8w8-99g7-qmvj

Vendor Advisories for CVE-2026-54904(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(5 across 5 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
ruby-concurrent1.1.6+dfsg-3 ... 1.3.8-1 (16 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
ruby-concurrent1.1.6+dfsg-5 ... 1.3.8-1 (14 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
ruby-concurrent1.3.5-1 ... 1.3.8-1 (7 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
ruby-concurrent1.3.5-1, 1.3.6-1
  • every version up to 1.3.7-1: fixed in 1.3.7-1
—
RubyGems(1)
PackageVulnerable rangeFix by version rangeDependents
concurrent-ruby0.0.1 ... 1.3.6 (77 versions)
  • every version up to 1.3.7: fixed in 1.3.7
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 7× in last 7d / 26× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 140 total refreshes for this CVE.

  1. 2026-10-06 15:18 UTCEPSS rescore
  2. 2026-10-05 17:43 UTCEPSS rescore
  3. 2026-10-04 23:22 UTCEPSS rescore
  4. 2026-10-03 14:26 UTCEPSS rescore
  5. 2026-10-03 04:39 UTCOSV refresh
  6. 2026-10-02 17:56 UTCEPSS rescore
  7. 2026-10-01 19:50 UTCEPSS rescore
  8. 2026-09-30 15:03 UTCEPSS rescore
  9. 2026-09-29 15:22 UTCEPSS rescore
  10. 2026-09-28 13:51 UTCEPSS rescore
  11. 2026-09-27 13:48 UTCEPSS rescore
  12. 2026-09-26 15:59 UTCEPSS rescore
  13. 2026-09-24 14:04 UTCEPSS rescore
  14. 2026-09-23 17:54 UTCEPSS rescore
  15. 2026-09-20 20:16 UTCEPSS rescore
  16. 2026-09-18 19:28 UTCEPSS rescore
  17. 2026-09-17 19:31 UTCEPSS rescore
  18. 2026-09-16 14:08 UTCEPSS rescore
  19. 2026-09-16 05:15 UTCEPSS rescore
  20. 2026-09-15 03:11 UTCEPSS rescore
  21. 2026-09-14 02:13 UTCEG score recompute
  22. 2026-09-13 16:47 UTCEPSS rescore
  23. 2026-09-13 13:01 UTCEG score recompute
  24. 2026-09-11 14:53 UTCEPSS rescore
  25. 2026-09-10 09:35 UTCEPSS rescore
Show 75 more
  1. 2026-09-08 22:01 UTCEPSS rescore
  2. 2026-09-07 16:01 UTCEPSS rescore
  3. 2026-09-06 13:47 UTCEPSS rescore
  4. 2026-09-04 05:06 UTCEPSS rescore
  5. 2026-09-02 14:12 UTCEPSS rescore
  6. 2026-09-01 13:54 UTCEPSS rescore
  7. 2026-09-01 04:40 UTCEPSS rescore
  8. 2026-08-30 20:46 UTCEG score recompute
  9. 2026-08-30 19:17 UTCEPSS rescore
  10. 2026-08-30 01:22 UTCEPSS rescore
  11. 2026-08-28 21:41 UTCEPSS rescore
  12. 2026-08-27 14:25 UTCEPSS rescore
  13. 2026-08-26 14:46 UTCEPSS rescore
  14. 2026-08-25 13:49 UTCEPSS rescore
  15. 2026-08-25 03:10 UTCEG score recompute
  16. 2026-08-24 14:18 UTCEG score recompute
  17. 2026-08-23 12:27 UTCEG score recompute
  18. 2026-08-23 00:19 UTCEPSS rescore
  19. 2026-08-22 23:37 UTCEG score recompute
  20. 2026-08-21 23:49 UTCEPSS rescore
  21. 2026-08-21 09:39 UTCEG score recompute
  22. 2026-08-20 22:55 UTCEPSS rescore
  23. 2026-08-20 07:59 UTCEG score recompute
  24. 2026-08-19 17:04 UTCEPSS rescore
  25. 2026-08-19 07:00 UTCEG score recompute
  26. 2026-08-18 13:48 UTCEPSS rescore
  27. 2026-08-17 13:47 UTCEPSS rescore
  28. 2026-08-17 00:27 UTCEG score recompute
  29. 2026-08-16 14:56 UTCEPSS rescore
  30. 2026-08-16 11:36 UTCEG score recompute
  31. 2026-08-16 02:14 UTCEPSS rescore
  32. 2026-08-15 09:57 UTCEG score recompute
  33. 2026-08-15 01:30 UTCEPSS rescore
  34. 2026-08-14 08:18 UTCEG score recompute
  35. 2026-08-13 22:00 UTCEPSS rescore
  36. 2026-08-12 17:39 UTCEG score recompute
  37. 2026-08-12 13:51 UTCEPSS rescore
  38. 2026-08-11 15:40 UTCEG score recompute
  39. 2026-08-11 02:49 UTCEG score recompute
  40. 2026-08-11 00:00 UTCEPSS rescore
  41. 2026-08-10 01:10 UTCEG score recompute
  42. 2026-08-09 13:46 UTCEPSS rescore
  43. 2026-08-08 23:31 UTCEG score recompute
  44. 2026-08-08 16:37 UTCEPSS rescore
  45. 2026-08-07 21:52 UTCEG score recompute
  46. 2026-08-06 20:12 UTCEG score recompute
  47. 2026-08-06 13:47 UTCEPSS rescore
  48. 2026-08-06 07:22 UTCEG score recompute
  49. 2026-08-05 19:17 UTCEPSS rescore
  50. 2026-08-05 18:32 UTCEG score recompute
  51. 2026-08-05 17:57 UTCEG score recompute
  52. 2026-08-04 15:19 UTCEG score recompute
  53. 2026-08-04 15:10 UTCEPSS rescore
  54. 2026-08-04 10:39 UTCEPSS rescore
  55. 2026-08-02 06:41 UTCEG score recompute
  56. 2026-08-02 02:27 UTCEPSS rescore
  57. 2026-08-01 05:01 UTCEG score recompute
  58. 2026-08-01 04:16 UTCEPSS rescore
  59. 2026-07-30 22:18 UTCEG score recompute
  60. 2026-07-30 16:28 UTCEPSS rescore
  61. 2026-07-30 03:16 UTCEG score recompute
  62. 2026-07-30 01:30 UTCEPSS rescore
  63. 2026-07-29 01:33 UTCEG score recompute
  64. 2026-07-28 15:37 UTCEPSS rescore
  65. 2026-07-27 21:19 UTCEG score recompute
  66. 2026-07-26 16:47 UTCEG score recompute
  67. 2026-07-26 14:54 UTCEPSS rescore
  68. 2026-07-25 14:18 UTCEPSS rescore
  69. 2026-07-24 14:18 UTCEPSS rescore
  70. 2026-07-23 14:18 UTCEPSS rescore
  71. 2026-07-23 03:20 UTCEG score recompute
  72. 2026-07-22 14:08 UTCEPSS rescore
  73. 2026-07-21 15:25 UTCEPSS rescore
  74. 2026-07-20 17:08 UTCEPSS rescore
  75. 2026-07-19 14:31 UTCEPSS rescore

Related CVEs(same product + same CWE)

Same product

2 shown

Debian:11:ruby-concurrent

Frequently asked(5)

What is CVE-2026-54904?
CVE-2026-54904 is a high vulnerability published on June 19, 2026. 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 compareandset(oldvalue,…
When was CVE-2026-54904 disclosed?
CVE-2026-54904 was first published on June 19, 2026, with the most recent update on August 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-54904 actively exploited?
CVE-2026-54904 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.7% probability of exploitation in the next 30 days (50th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-54904?
CVE-2026-54904 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-54904?
A fix for CVE-2026-54904 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-54904 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-54904

Explore →

Is Your Infrastructure Affected by CVE-2026-54904?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs