CVE-2026-23830

CRITICALNVD 10.010.0
EchelonGraph scoreMEDIUM confidence

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

Score 10.0 from GitHub Security Advisory (severity: CRITICAL) published 2026-01-27. NVD baseline CVSS 10.0; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Elevated

Also known asEUVD-2026-4897 (ENISA EUVD) · GHSA-wxhw-j4hc-fmq6 (GitHub Security Advisories)Source: ENISA EUVD

10.0EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (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: 1.2%CVSS: 10.0Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

SandboxJS is a JavaScript sandboxing library. Versions prior to 0.8.26 have a sandbox escape vulnerability due to AsyncFunction not being isolated in SandboxFunction. The library attempts to sandbox code execution by replacing the global Function constructor with a safe, sandboxed version (SandboxFunction). This is handled in utils.ts by mapping Function to sandboxFunction within a map used for lookups. However, before version 0.8.26, the library did not include mappings for AsyncFunction, GeneratorFunction, and AsyncGeneratorFunction. These constructors are not global properties but can be accessed via the .constructor property of an instance (e.g., (async () => {}).constructor). In executor.ts, property access is handled. When code running inside the sandbox accesses .constructor on an async function (which the sandbox allows creating), the executor retrieves the property value. Since AsyncFunction was not in the safe-replacement map, the executor returns the actual native host AsyncFunction constructor. Constructors for functions in JavaScript (like Function, AsyncFunction) create functions that execute in the global scope. By obtaining the host AsyncFunction constructor, an attacker can create a new async function that executes entirely outside the sandbox context, bypassing all restrictions and gaining full access to the host environment (Remote Code Execution). Version 0.8.26 patches this vulnerability.

CVSS v3
10.0
EG Score
10.0CRITICALmedium confidence
EG Risk
76
EG Risk 76/100

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)
Severity100% × 45%
Impact severity (EG Severity): CVSS 10.0 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, Track* at medium and Attend at high mission impact.
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (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: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
1.2%
EPSS %ILE
69th
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 (10.0): severity, escalated by confirmed exploitation. This CVE's 10.0 is its impact severity (EG Severity), not escalated.

EG Severity
10.0 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
1.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-12). 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, Track* at medium and Attend at high mission impact.CISA BOD 26-04: 3 days if the affected system is publicly exposed; 60 days if it is not.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, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (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)3 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (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

January 28, 2026

Last Modified

June 17, 2026

Advisory Details (2)

Auto-updated Nov 8, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit.
GitHub advisoryMentions a patch (unverified)🟡 PoC Available

Sandbox Escape · Advisory · nyariv/SandboxJS · GitHub

https://github.com/nyariv/SandboxJS/security/advisories/GHSA-wxhw-j4hc-fmq6
GitHub commit Patch Available

commit 345aee6566e4 (nyariv/SandboxJS)

Patch available: nyariv/SandboxJS v0.8.32 (contains commit 345aee6566e4)

https://github.com/nyariv/SandboxJS/commit/345aee6566e47979dee5c337b925b141e7f78ccd

Vendor Advisories for CVE-2026-23830(1)

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

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
npm@nyariv/sandboxjs @ 0.8.26 (fixes < 0.8.26)—ghsa

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFix by version rangeDependents
@nyariv/sandboxjs—
  • every version up to 0.8.26: fixed in 0.8.26
—

Weakness Classification(3)

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

Data Freshness Timeline

(refreshed 15× in last 7d / 44× 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 261 rows on record for this CVE.

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. None are among the latest 100 rows. The 161 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-12 23:26 UTCEchelonGraph re-scored
  2. 2026-11-12 23:26 UTCGHSA enrichmentGHSA-wxhw-j4hc-fmq6 · GitHub severity CRITICAL · GitHub CVSS 10.0
  3. 2026-11-12 16:33 UTCEPSS rescoreEPSS 1.2% · 69th percentile
  4. 2026-11-12 01:36 UTCEchelonGraph re-scored
  5. 2026-11-12 01:36 UTCGHSA enrichmentGHSA-wxhw-j4hc-fmq6 · GitHub severity CRITICAL · GitHub CVSS 10.0
  6. 2026-11-11 16:39 UTCEPSS rescoreEPSS 1.2% · 69th percentile
  7. 2026-11-11 03:46 UTCEchelonGraph re-scored
  8. 2026-11-11 03:46 UTCGHSA enrichmentGHSA-wxhw-j4hc-fmq6 · GitHub severity CRITICAL · GitHub CVSS 10.0
  9. 2026-11-10 16:43 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  10. 2026-11-10 05:55 UTCEchelonGraph re-scored
  11. 2026-11-10 05:55 UTCGHSA enrichmentGHSA-wxhw-j4hc-fmq6 · GitHub severity CRITICAL · GitHub CVSS 10.0
  12. 2026-11-09 16:34 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  13. 2026-11-09 08:05 UTCEchelonGraph re-scored
  14. 2026-11-09 08:05 UTCGHSA enrichmentGHSA-wxhw-j4hc-fmq6 · GitHub severity CRITICAL · GitHub CVSS 10.0
  15. 2026-11-08 16:38 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  16. 2026-11-08 10:14 UTCEchelonGraph re-scored
  17. 2026-11-08 10:14 UTCGHSA enrichmentGHSA-wxhw-j4hc-fmq6 · GitHub severity CRITICAL · GitHub CVSS 10.0
  18. 2026-11-07 16:38 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  19. 2026-11-07 12:20 UTCEchelonGraph re-scored
  20. 2026-11-07 12:20 UTCGHSA enrichmentGHSA-wxhw-j4hc-fmq6 · GitHub severity CRITICAL · GitHub CVSS 10.0
  21. 2026-11-06 16:37 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  22. 2026-11-06 14:30 UTCGHSA enrichmentGHSA-wxhw-j4hc-fmq6 · GitHub severity CRITICAL · GitHub CVSS 10.0
  23. 2026-11-06 03:25 UTCOSV refresh
  24. 2026-11-05 16:40 UTCEchelonGraph re-scored
  25. 2026-11-05 16:40 UTCGHSA enrichmentGHSA-wxhw-j4hc-fmq6 · GitHub severity CRITICAL · GitHub CVSS 10.0
Show 75 more
  1. 2026-11-05 16:37 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  2. 2026-11-04 18:49 UTCEchelonGraph re-scored
  3. 2026-11-04 18:49 UTCGHSA enrichmentGHSA-wxhw-j4hc-fmq6 · GitHub severity CRITICAL · GitHub CVSS 10.0
  4. 2026-11-04 16:35 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  5. 2026-11-03 20:58 UTCEchelonGraph re-scored
  6. 2026-11-03 20:58 UTCGHSA enrichmentGHSA-wxhw-j4hc-fmq6 · GitHub severity CRITICAL · GitHub CVSS 10.0
  7. 2026-11-03 16:47 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  8. 2026-11-02 23:07 UTCEchelonGraph re-scored
  9. 2026-11-02 23:07 UTCGHSA enrichmentGHSA-wxhw-j4hc-fmq6 · GitHub severity CRITICAL · GitHub CVSS 10.0
  10. 2026-11-02 16:44 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  11. 2026-11-02 01:17 UTCEchelonGraph re-scored
  12. 2026-11-02 01:17 UTCGHSA enrichmentGHSA-wxhw-j4hc-fmq6 · GitHub severity CRITICAL · GitHub CVSS 10.0
  13. 2026-11-01 07:57 UTCGHSA enrichmentGHSA-wxhw-j4hc-fmq6 · GitHub severity CRITICAL · GitHub CVSS 10.0
  14. 2026-11-01 07:57 UTCEchelonGraph re-scored
  15. 2026-11-01 03:26 UTCEchelonGraph re-scored
  16. 2026-10-31 16:32 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  17. 2026-10-31 05:35 UTCEchelonGraph re-scored
  18. 2026-10-30 16:34 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  19. 2026-10-30 07:45 UTCEchelonGraph re-scored
  20. 2026-10-29 16:32 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  21. 2026-10-29 09:55 UTCEchelonGraph re-scored
  22. 2026-10-28 16:31 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  23. 2026-10-28 12:03 UTCEchelonGraph re-scored
  24. 2026-10-27 16:31 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  25. 2026-10-27 14:13 UTCEchelonGraph re-scored
  26. 2026-10-26 16:31 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  27. 2026-10-25 17:55 UTCEchelonGraph re-scored
  28. 2026-10-25 16:32 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  29. 2026-10-25 14:41 UTCEchelonGraph re-scored
  30. 2026-10-24 19:31 UTCEchelonGraph re-scored
  31. 2026-10-24 16:32 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  32. 2026-10-23 21:41 UTCEchelonGraph re-scored
  33. 2026-10-23 16:31 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  34. 2026-10-22 23:47 UTCEchelonGraph re-scored
  35. 2026-10-22 16:34 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  36. 2026-10-22 01:53 UTCEchelonGraph re-scored
  37. 2026-10-21 16:32 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  38. 2026-10-21 04:01 UTCEchelonGraph re-scored
  39. 2026-10-20 16:32 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  40. 2026-10-20 06:05 UTCEchelonGraph re-scored
  41. 2026-10-19 16:31 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  42. 2026-10-19 08:05 UTCEchelonGraph re-scored
  43. 2026-10-18 16:31 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  44. 2026-10-18 03:54 UTCEchelonGraph re-scored
  45. 2026-10-17 16:33 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  46. 2026-10-17 11:04 UTCEchelonGraph re-scored
  47. 2026-10-16 16:41 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  48. 2026-10-16 12:57 UTCEchelonGraph re-scored
  49. 2026-10-15 16:31 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  50. 2026-10-15 15:05 UTCEchelonGraph re-scored
  51. 2026-10-14 16:32 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  52. 2026-10-14 09:32 UTCEchelonGraph re-scored
  53. 2026-10-13 16:33 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  54. 2026-10-13 07:07 UTCEchelonGraph re-scored
  55. 2026-10-12 16:33 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  56. 2026-10-12 16:20 UTCEchelonGraph re-scored
  57. 2026-10-11 20:02 UTCEchelonGraph re-scored
  58. 2026-10-11 17:16 UTCEchelonGraph re-scored
  59. 2026-10-11 14:47 UTCEchelonGraph re-scored
  60. 2026-10-11 13:48 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  61. 2026-10-10 20:00 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  62. 2026-10-09 20:07 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  63. 2026-10-09 09:58 UTCOSV refresh
  64. 2026-10-08 17:11 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  65. 2026-10-07 23:47 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  66. 2026-10-06 15:17 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  67. 2026-10-05 17:42 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  68. 2026-10-04 23:21 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  69. 2026-10-01 19:49 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  70. 2026-09-30 15:03 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  71. 2026-09-29 15:21 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  72. 2026-09-28 13:51 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  73. 2026-09-27 13:47 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  74. 2026-09-26 15:58 UTCEPSS rescoreEPSS 1.2% · 68th percentile
  75. 2026-09-26 00:26 UTCEPSS rescoreEPSS 1.2% · 68th percentile

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Frequently asked(5)

What is CVE-2026-23830?
CVE-2026-23830 is a critical-severity vulnerability; its CVE record was published on January 28, 2026. SandboxJS is a JavaScript sandboxing library. Versions prior to 0.8.26 have a sandbox escape vulnerability due to AsyncFunction not being isolated in SandboxFunction. The library attempts to sandbox code execution by replacing the global Function constructor with a safe, sandboxed version…
When was the CVE record for CVE-2026-23830 published?
The CVE record for CVE-2026-23830 was published on January 28, 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 June 17, 2026; the record at its source may have been updated since.
Is CVE-2026-23830 actively exploited?
CVE-2026-23830 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.2% probability of exploitation in the next 30 days (69th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-23830?
CVE-2026-23830 has a CVSS v3 base score of 10.0 (NVD).
How do I remediate CVE-2026-23830?
A fix for CVE-2026-23830 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-23830 are linked in the Vendor Advisories panel on this page.

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