CVE-2026-58253

HIGHPre-NVD 8.88.8
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 8.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4% (28th 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
8.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 8.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.0, 2.12.7, and 2.11.16, when no_auth_user was configured, a parser fast path intended for ordinary client connections could also apply to route or leafnode listeners, allowing an unauthenticated peer to bypass inter-server CONNECT authentication and operate with the privileges associated with that connection type. This issue is fixed in versions 2.14.0, 2.12.7, and 2.11.16.

CVSS v3
8.8
EG Score
8.8HIGHmedium confidence
EG Risk
40
EG Risk 40/100

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)
Severity88% × 45%
The EG Score, 8.8 of 10.
Exploitation0.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (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: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.4%
EPSS %ILE
28th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (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)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (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 8, 2026

Last Modified

July 13, 2026

Advisory Details (7)

Auto-updated Jul 8, 2026
Patch available. Sources: github_commit, github_release, github.
GitHub advisoryMentions a patch (unverified)

Route API Auth Bypass · Advisory · nats-io/nats-server · GitHub

Affected: v2.14.0, v2.12.7 and v2.11.16.

https://github.com/nats-io/nats-server/security/advisories/GHSA-38x3-76xf-cq45
GitHub release Patch Available

Release v2.14.0

Patch available: nats-io/nats-server v2.14.0

https://github.com/nats-io/nats-server/releases/tag/v2.14.0
GitHub release Patch Available

Release v2.12.7

Patch available: nats-io/nats-server v2.12.7

https://github.com/nats-io/nats-server/releases/tag/v2.12.7
GitHub release Patch Available

Release v2.11.16

Patch available: nats-io/nats-server v2.11.16

https://github.com/nats-io/nats-server/releases/tag/v2.11.16
GitHub commit

commit b86147e81710 (nats-io/nats-server)

Fix landed in nats-io/nats-server commit b86147e81710 — awaiting tagged release

https://github.com/nats-io/nats-server/commit/b86147e81710a52b72a7f7275f91d69f723f5cb3
GitHub commit

commit 8b8e1ad4ceed (nats-io/nats-server)

Fix landed in nats-io/nats-server commit 8b8e1ad4ceed — awaiting tagged release

https://github.com/nats-io/nats-server/commit/8b8e1ad4ceed32321e00d4fc6e76be05bc13bca6
GitHub commit

commit 7b81dd455ea9 (nats-io/nats-server)

Fix landed in nats-io/nats-server commit 7b81dd455ea9 — awaiting tagged release

https://github.com/nats-io/nats-server/commit/7b81dd455ea95960090a84858c7662827948d1b6

Vendor Advisories for CVE-2026-58253(1)

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

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
nats-server2.10.1-1 ... 2.9.19-1 (15 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
nats-server2.10.27-1 ... 2.14.6-1 (6 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
nats-server2.10.27-1, 2.12.4-1, 2.12.6-1
  • every version up to 2.14.1-1: fixed in 2.14.1-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 40× 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 100 of 222 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. None are among the latest 100 rows. The 122 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  2. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  3. 2026-10-12 15:53 UTCEG score recompute
  4. 2026-10-11 19:36 UTCEG score recompute
  5. 2026-10-11 16:52 UTCEG score recompute
  6. 2026-10-11 14:14 UTCEG score recompute
  7. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  9. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  10. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  11. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  12. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  13. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  14. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  15. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  16. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  17. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  18. 2026-10-01 16:10 UTCEG score recompute
  19. 2026-10-01 16:10 UTCVendor advisory
  20. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  21. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  22. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  23. 2026-09-28 13:21 UTCEG score recompute
  24. 2026-09-28 13:21 UTCVendor advisory
  25. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.4% · 28th percentile
Show 75 more
  1. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  2. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  3. 2026-09-24 11:47 UTCEG score recompute
  4. 2026-09-24 11:47 UTCVendor advisory
  5. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  6. 2026-09-23 06:07 UTCEG score recompute
  7. 2026-09-23 06:07 UTCVendor advisory
  8. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  9. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  10. 2026-09-18 05:43 UTCEG score recompute
  11. 2026-09-18 05:43 UTCVendor advisory
  12. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  13. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  14. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  15. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  16. 2026-09-14 11:15 UTCVendor advisory
  17. 2026-09-13 23:49 UTCEG score recompute
  18. 2026-09-13 23:49 UTCVendor advisory
  19. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  20. 2026-09-13 08:24 UTCEG score recompute
  21. 2026-09-13 08:24 UTCVendor advisory
  22. 2026-09-12 14:34 UTCVendor advisory
  23. 2026-09-12 03:31 UTCEG score recompute
  24. 2026-09-12 03:31 UTCVendor advisory
  25. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  26. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  27. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  28. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  29. 2026-09-06 14:02 UTCEG score recompute
  30. 2026-09-06 14:02 UTCVendor advisory
  31. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  32. 2026-09-05 22:47 UTCEG score recompute
  33. 2026-09-05 22:47 UTCVendor advisory
  34. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  35. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  36. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  37. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  38. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  39. 2026-08-30 18:32 UTCVendor advisory
  40. 2026-08-30 07:29 UTCEG score recompute
  41. 2026-08-30 07:29 UTCVendor advisory
  42. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  43. 2026-08-28 21:42 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  44. 2026-08-27 21:49 UTCEG score recompute
  45. 2026-08-27 21:49 UTCVendor advisory
  46. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  47. 2026-08-27 01:26 UTCEG score recompute
  48. 2026-08-27 01:26 UTCVendor advisory
  49. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  50. 2026-08-26 08:21 UTCEG score recompute
  51. 2026-08-26 08:21 UTCVendor advisory
  52. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  53. 2026-08-25 10:11 UTCVendor advisory
  54. 2026-08-24 21:44 UTCEG score recompute
  55. 2026-08-24 21:44 UTCVendor advisory
  56. 2026-08-24 10:10 UTCEG score recompute
  57. 2026-08-24 10:10 UTCVendor advisory
  58. 2026-08-23 23:05 UTCVendor advisory
  59. 2026-08-23 11:39 UTCVendor advisory
  60. 2026-08-23 00:36 UTCEG score recompute
  61. 2026-08-23 00:36 UTCVendor advisory
  62. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  63. 2026-08-22 13:11 UTCVendor advisory
  64. 2026-08-22 02:08 UTCEG score recompute
  65. 2026-08-22 02:08 UTCVendor advisory
  66. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  67. 2026-08-21 03:59 UTCEG score recompute
  68. 2026-08-21 03:59 UTCVendor advisory
  69. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  70. 2026-08-20 15:37 UTCVendor advisory
  71. 2026-08-20 01:58 UTCEG score recompute
  72. 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  73. 2026-08-19 09:32 UTCVendor advisory
  74. 2026-08-18 22:28 UTCVendor advisory
  75. 2026-08-18 10:49 UTCVendor advisory

Frequently asked(5)

What is CVE-2026-58253?
CVE-2026-58253 is a high-severity vulnerability; its CVE record was published on July 8, 2026. NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.0, 2.12.7, and 2.11.16, when noauthuser was configured, a parser fast path intended for ordinary client connections could also apply to route or leafnode listeners, allowing an…
When was the CVE record for CVE-2026-58253 published?
The CVE record for CVE-2026-58253 was published on July 8, 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 13, 2026; the record at its source may have been updated since.
Is CVE-2026-58253 actively exploited?
CVE-2026-58253 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (28th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-58253?
CVE-2026-58253 has a CVSS base score of 8.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-58253?
A fix for CVE-2026-58253 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-58253 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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