CVE-2026-38976

HIGHPre-NVD 7.57.5
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-07-07. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: CISA-ADP (Vulnrichment) CVSS v3.1, EPSS, GitHub Security Advisory
Elevated

Also known asEUVD-2026-41977 (ENISA EUVD) · GHSA-ff2c-rpvx-jp6m (GitHub Security Advisories)Source: ENISA EUVD

7.5EG
EchelonGraph verdictPlan mitigationThe upstream fix is not in a release yet: until the release ships, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule at low or medium mission impact and sooner than that at high, then apply it (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.6%CVSS: 7.5Exploit: No code on recordExposed services: Not assessed

An upstream fix is merged but not yet released — mitigate (WAF / firewall / segmentation) until the release ships, then apply it.

mrubyc through 3.4.1 was found to contain a NULL pointer dereference in src/vm.c in op_super() / OP_SUPER due to a missing runtime guard for top-level super.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
65
EG Risk 65/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity75% × 45%
Impact severity (EG Severity): CVSS 7.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: An upstream fix is merged but not yet in a tagged release. Until the release ships, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule at low or medium mission impact and sooner than that at high, then apply it.
EPSS PROB
0.6%
EPSS %ILE
49th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.

EG Severity
7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.6% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-08). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

An upstream fix is merged but not yet in a tagged release. Until the release ships, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule at low or medium mission impact and sooner than that at high, then apply it.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.

No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

July 6, 2026

Last Modified

July 7, 2026

Advisory Details (3)

Auto-updated Jul 7, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit.
Web page

[BUG] Null pointer dereference in `OP_SUPER` via missing runtime guard for top-level `super` · Issue #276 · mrubyc/mrubyc · GitHub

https://github.com/mrubyc/mrubyc/issues/276
Web page

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

https://github.com/mrubyc/mrubyc
GitHub commit

commit c4aa2a06bfdd (hayat01sh1da/mrubyc)

Fix landed in hayat01sh1da/mrubyc commit c4aa2a06bfdd — awaiting tagged release

https://github.com/hayat01sh1da/mrubyc/commit/c4aa2a06bfdd13a0f1ae5165c5760a2530314a42

Vendor Advisories for CVE-2026-38976(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 / 34× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed its CVE.org record (CNA or CISA ADP). An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 271 rows on record for this CVE, as 99 entries (1 repeat merged).

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 1 repeat row among the latest 100 is merged into the row it repeats. The 171 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 16:52 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  2. 2026-11-12 16:33 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  3. 2026-11-11 16:39 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  4. 2026-11-10 16:43 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  5. 2026-11-09 16:35 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  6. 2026-11-09 02:54 UTCEchelonGraph re-scored
  7. 2026-11-09 02:54 UTCGHSA enrichmentGHSA-ff2c-rpvx-jp6m · GitHub severity HIGH · GitHub CVSS 7.5
  8. 2026-11-08 16:39 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  9. 2026-11-07 16:39 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  10. 2026-11-06 16:37 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  11. 2026-11-05 16:37 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  12. 2026-11-04 16:35 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  13. 2026-11-03 16:48 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  14. 2026-11-02 16:44 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  15. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  16. 2026-11-01 14:59 UTCEchelonGraph re-scored
  17. 2026-11-01 14:59 UTCGHSA enrichmentGHSA-ff2c-rpvx-jp6m · GitHub severity HIGH · GitHub CVSS 7.5
  18. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  19. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  20. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  21. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  22. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  23. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  24. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  25. 2026-10-25 14:32 UTCEchelonGraph re-scored
Show 74 more
  1. 2026-10-25 03:03 UTCEchelonGraph re-scored
  2. 2026-10-25 03:03 UTCGHSA enrichmentGHSA-ff2c-rpvx-jp6m · GitHub severity HIGH · GitHub CVSS 7.5
  3. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  4. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  5. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  6. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  7. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  8. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  9. 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  10. 2026-10-18 03:44 UTCEchelonGraph re-scored
  11. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  12. 2026-10-17 15:07 UTCEchelonGraph re-scored
  13. 2026-10-17 15:07 UTCGHSA enrichmentGHSA-ff2c-rpvx-jp6m · GitHub severity HIGH · GitHub CVSS 7.5
  14. 2026-10-16 16:41 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  15. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  16. 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  17. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  18. 2026-10-13 13:54 UTCOSV refresh
  19. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  20. 2026-10-12 16:10 UTCEchelonGraph re-scored
  21. 2026-10-11 19:52 UTCEchelonGraph re-scored
  22. 2026-10-11 17:06 UTCEchelonGraph re-scored
  23. 2026-10-11 14:32 UTCEchelonGraph re-scored
  24. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  25. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  26. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  27. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  28. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  29. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  30. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  31. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  32. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  33. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  34. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  35. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  36. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  37. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  38. 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  39. 2026-09-23 06:27 UTCEchelonGraph re-scored
  40. 2026-09-23 06:27 UTCGHSA enrichmentGHSA-ff2c-rpvx-jp6m · GitHub severity HIGH · GitHub CVSS 7.5
  41. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  42. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  43. 2026-09-18 06:06 UTCEchelonGraph re-scored
  44. 2026-09-18 06:06 UTCGHSA enrichmentGHSA-ff2c-rpvx-jp6m · GitHub severity HIGH · GitHub CVSS 7.5
  45. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  46. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  47. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  48. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  49. 2026-09-13 23:58 UTCEchelonGraph re-scored
  50. 2026-09-13 23:58 UTCGHSA enrichmentGHSA-ff2c-rpvx-jp6m · GitHub severity HIGH · GitHub CVSS 7.5
  51. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  52. 2026-09-13 08:47 UTCEchelonGraph re-scored
  53. 2026-09-13 08:47 UTCGHSA enrichmentGHSA-ff2c-rpvx-jp6m · GitHub severity HIGH · GitHub CVSS 7.5
  54. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  55. 2026-09-12 13:42 UTCEchelonGraph re-scored
  56. 2026-09-12 13:42 UTCGHSA enrichmentGHSA-ff2c-rpvx-jp6m · GitHub severity HIGH · GitHub CVSS 7.5
  57. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  58. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  59. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  60. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  61. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  62. 2026-09-06 14:13 UTCEchelonGraph re-scored
  63. 2026-09-06 14:13 UTCGHSA enrichmentGHSA-ff2c-rpvx-jp6m · GitHub severity HIGH · GitHub CVSS 7.5
  64. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  65. 2026-09-05 23:15 UTCEchelonGraph re-scored
  66. 2026-09-05 23:15 UTCGHSA enrichmentGHSA-ff2c-rpvx-jp6m · GitHub severity HIGH · GitHub CVSS 7.5
  67. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  68. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  69. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  70. 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  71. 2026-08-30 21:52 UTCEchelonGraph re-scored
  72. 2026-08-30 21:52 UTCGHSA enrichmentGHSA-ff2c-rpvx-jp6m · GitHub severity HIGH · GitHub CVSS 7.5
  73. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  74. 2026-08-30 08:30 UTCEchelonGraph re-scored

Frequently asked(5)

What is CVE-2026-38976?
CVE-2026-38976 is a high-severity vulnerability; its CVE record was published on July 6, 2026. mrubyc through 3.4.1 was found to contain a NULL pointer dereference in src/vm.c in op_super() / OP_SUPER due to a missing runtime guard for top-level super.
When was the CVE record for CVE-2026-38976 published?
The CVE record for CVE-2026-38976 was published on July 6, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of July 7, 2026; the record at its source may have been updated since.
Is CVE-2026-38976 actively exploited?
CVE-2026-38976 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.6% probability of exploitation in the next 30 days (49th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-38976?
CVE-2026-38976 has a CVSS v3.1 base score of 7.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-38976?
An upstream fix for CVE-2026-38976 has been merged but is not yet in a tagged release. Until it ships, restrict network exposure of the affected system or apply the vendor's mitigation, then update to the release that contains the fix. The vendor advisories EchelonGraph has for CVE-2026-38976 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-38976

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