CVE-2026-38973

MEDIUMPre-NVD 4.44.4—
EchelonGraph scoreMEDIUM confidence

Score 4.4 from GitHub Security Advisory published 2026-07-07. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 4.4; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this week
4.4EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.4Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

mrubyc through release3.4.1 was found to contain an out-of-bounds read in builtin missing-method lookup inside mrbc_find_method().

CVSS v3
4.4
EG Score
4.4(medium)
EG Risk
20(Track)
EG Risk 20/100SSVC: Track

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
Severity44% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
6%
KEV
Not listed

Published

July 6, 2026

Last Modified

July 9, 2026

Advisory Details (3)

Auto-updated Jul 9, 2026
Patch available. Sources: github_commit.
generic

Issues · mrubyc/mrubyc · GitHub

https://github.com/mrubyc/mrubyc/issues/279%2C
github_commit Patch Available

commit f83a8b67ca1c (mrubyc/mrubyc)

Patch available: mrubyc/mrubyc release4.0.0 (contains commit f83a8b67ca1c)

https://github.com/mrubyc/mrubyc/commit/f83a8b67ca1c7c62ac0dd548a363d79f767c4e30
generic

GitHub - mrubyc/mrubyc: mruby/c is another implementation of mruby. · GitHub

https://github.com/mrubyc/mrubyc

Vendor Advisories for CVE-2026-38973(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 56× 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 146 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-38973?
CVE-2026-38973 is a medium vulnerability published on July 6, 2026. mrubyc through release3.4.1 was found to contain an out-of-bounds read in builtin missing-method lookup inside mrbcfindmethod().
When was CVE-2026-38973 disclosed?
CVE-2026-38973 was first published in the National Vulnerability Database on July 6, 2026, with the most recent update on July 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-38973 actively exploited?
CVE-2026-38973 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 94.1% of all scored CVEs.
What is the CVSS score of CVE-2026-38973?
CVE-2026-38973 has a CVSS v3.1 base score of 4.4 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-38973?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-38973, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-38973

Explore →

Is Your Infrastructure Affected by CVE-2026-38973?

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

Start Free Scan →Browse All CVEs