CVE-2026-58399

HIGHPre-NVD 8.78.7
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 8.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 1.0% (61st percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
8.7EG
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).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1.0%CVSS: 8.7Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

@acastellon/auth is an authentication control system for microservices. Versions prior to 2.3.0 appear to allow an unauthenticated authentication bypass in validateToken() through spoofable auth-user and Host request headers. The validateToken middleware contains a service-to-service bypass for auth-user: service-brother when req.get('host').startsWith(getHostName()). Both values involved in the check can be influenced by an unauthenticated HTTP client: auth-user is a request header, and Host is also client-controlled. As a result, a remote unauthenticated attacker can send a request with crafted headers and bypass token validation before the normal legacy/JWT/OIDC validation logic runs. A fix has been implemented in v2.3.0.

CVSS v3
8.7
EG Score
8.7HIGHmedium confidence
EG Risk
55
EG Risk 55/100

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 (value × EchelonGraph’s weight)
Severity87% × 45%
The EG Score, 8.7 of 10.
Exploitation1.0% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
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 none (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
1.0%
EPSS %ILE
61st
KEV
Not listed

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

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

Exploitation none (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.

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

June 18, 2026

Last Modified

July 2, 2026

Advisory Details (2)

Auto-updated Jul 2, 2026
Patch available. Sources: github.
GitHub advisoryMentions a patch (unverified)

Authentication bypass in @acastellon/auth v2.2.0 via spoofable headers in validateToken() (fixed in v2.3.0) · Advisory · antonio-castellon/module-auth · GitHub

Affected: v2.3.0) · Advisory · antonio-castellon/module-auth · GitHub

https://github.com/antonio-castellon/module-auth/security/advisories/GHSA-gfj5-979r-92pw
Web page

SECURITY: Authentication bypass in @acastellon/auth v2.2.0 via spoofable headers in validateToken() (mTLS fix in 2.3.0+) · Issue #6 · antonio-castellon/module-auth · GitHub

https://github.com/antonio-castellon/module-auth/issues/6

Vendor Advisories for CVE-2026-58399(1)

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

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFix by version rangeDependents
@acastellon/auth—
  • every version up to 2.3.0: fixed in 2.3.0
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 31× 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 it from the CNA feed. 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). Most recent first.

Showing the most recent 99 of 147 refreshes 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. 1 repeat row among the latest 100 is merged into the row it repeats. The 48 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-14 16:33 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  2. 2026-10-13 16:34 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  3. 2026-10-12 16:34 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  4. 2026-10-12 15:53 UTCEG score recompute
  5. 2026-10-11 19:36 UTCEG score recompute
  6. 2026-10-11 16:52 UTCEG score recompute
  7. 2026-10-11 14:14 UTCEG score recompute
  8. 2026-10-11 13:49 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  9. 2026-10-10 20:00 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  10. 2026-10-09 20:07 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  11. 2026-10-08 17:13 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  12. 2026-10-07 23:48 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  13. 2026-10-06 15:18 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  14. 2026-10-05 17:43 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  15. 2026-10-04 23:22 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  16. 2026-10-03 14:26 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  17. 2026-10-02 17:56 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  18. 2026-10-01 19:50 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  19. 2026-09-30 15:03 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  20. 2026-09-29 15:22 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  21. 2026-09-28 13:51 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  22. 2026-09-27 13:48 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  23. 2026-09-26 15:59 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  24. 2026-09-24 14:04 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  25. 2026-09-23 17:54 UTCEPSS rescoreEPSS 1.0% · 60th percentile
Show 74 more
  1. 2026-09-20 20:16 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  2. 2026-09-18 19:28 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  3. 2026-09-17 19:31 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  4. 2026-09-16 14:08 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  5. 2026-09-16 05:15 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  6. 2026-09-15 03:11 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  7. 2026-09-14 02:17 UTCEG score recompute
  8. 2026-09-13 16:47 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  9. 2026-09-13 13:53 UTCEG score recompute
  10. 2026-09-11 14:53 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  11. 2026-09-10 09:35 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  12. 2026-09-08 22:01 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  13. 2026-09-07 16:01 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  14. 2026-09-06 13:47 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  15. 2026-09-04 05:07 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  16. 2026-09-02 14:12 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  17. 2026-09-01 13:54 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  18. 2026-09-01 04:40 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  19. 2026-08-30 20:55 UTCEG score recompute
  20. 2026-08-30 19:17 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  21. 2026-08-30 01:22 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  22. 2026-08-28 21:42 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  23. 2026-08-27 14:25 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  24. 2026-08-26 14:46 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  25. 2026-08-25 13:49 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  26. 2026-08-24 14:49 UTCEG score recompute
  27. 2026-08-23 01:07 UTCEG score recompute
  28. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  29. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  30. 2026-08-21 07:22 UTCEG score recompute
  31. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  32. 2026-08-20 08:08 UTCEG score recompute
  33. 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  34. 2026-08-19 07:42 UTCEG score recompute
  35. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  36. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  37. 2026-08-16 20:40 UTCEG score recompute
  38. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  39. 2026-08-16 08:31 UTCEG score recompute
  40. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  41. 2026-08-15 09:04 UTCEG score recompute
  42. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  43. 2026-08-14 07:24 UTCEG score recompute
  44. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  45. 2026-08-12 21:13 UTCEG score recompute
  46. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  47. 2026-08-11 22:16 UTCEG score recompute
  48. 2026-08-11 10:52 UTCEG score recompute
  49. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  50. 2026-08-10 00:39 UTCEG score recompute
  51. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  52. 2026-08-09 01:52 UTCEG score recompute
  53. 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  54. 2026-08-08 03:05 UTCEG score recompute
  55. 2026-08-06 16:53 UTCEG score recompute
  56. 2026-08-06 13:47 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  57. 2026-08-06 05:29 UTCEG score recompute
  58. 2026-08-05 19:17 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  59. 2026-08-04 15:23 UTCEG score recompute
  60. 2026-08-04 15:10 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  61. 2026-08-04 10:39 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  62. 2026-08-03 20:07 UTCEG score recompute
  63. 2026-08-03 10:36 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  64. 2026-08-02 07:49 UTCEG score recompute
  65. 2026-08-02 02:27 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  66. 2026-08-01 09:00 UTCEG score recompute
  67. 2026-08-01 04:16 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  68. 2026-07-30 22:26 UTCEG score recompute
  69. 2026-07-30 16:28 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  70. 2026-07-30 03:06 UTCEG score recompute
  71. 2026-07-30 01:30 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  72. 2026-07-29 01:44 UTCEG score recompute
  73. 2026-07-28 15:37 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  74. 2026-07-27 18:28 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-58399?
CVE-2026-58399 is a high-severity vulnerability; its CVE record was published on June 18, 2026. @acastellon/auth is an authentication control system for microservices. Versions prior to 2.3.0 appear to allow an unauthenticated authentication bypass in validateToken() through spoofable auth-user and Host request headers. The validateToken middleware contains a service-to-service bypass for…
When was the CVE record for CVE-2026-58399 published?
The CVE record for CVE-2026-58399 was published on June 18, 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 2, 2026; the record at its source may have been updated since.
Is CVE-2026-58399 actively exploited?
CVE-2026-58399 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.0% probability of exploitation in the next 30 days (61st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-58399?
CVE-2026-58399 has a CVSS base score of 8.7 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-58399?
A fix for CVE-2026-58399 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-58399 are linked in the Vendor Advisories panel on this page.

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