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.
CVE-2026-58253
“—” 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% (30th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
Also known asEUVD-2026-42375 (ENISA EUVD)Source: ENISA EUVD
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 8.8
- EG Score
- 8.8HIGHmedium confidence
- EG Risk
- 40EG Risk 40/100
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)Severity88% × 45%Impact severity (EG Severity): CVSS 8.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.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
- 30th
- 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 (8.8): severity, escalated by confirmed exploitation. This CVE's 8.8 is its impact severity (EG Severity), not escalated.
- EG Severity
- 8.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
- EG Likelihood
- 0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-01). 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 every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade 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 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.
The score's inputs: 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
October 25, 2026
Advisory Details (7)
Auto-updated Jul 8, 2026Route 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-cq45Release v2.14.0
Patch available: nats-io/nats-server v2.14.0
https://github.com/nats-io/nats-server/releases/tag/v2.14.0Release v2.12.7
Patch available: nats-io/nats-server v2.12.7
https://github.com/nats-io/nats-server/releases/tag/v2.12.7Release v2.11.16
Patch available: nats-io/nats-server v2.11.16
https://github.com/nats-io/nats-server/releases/tag/v2.11.16commit 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/b86147e81710a52b72a7f7275f91d69f723f5cb3commit 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/8b8e1ad4ceed32321e00d4fc6e76be05bc13bca6commit 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/7b81dd455ea95960090a84858c7662827948d1b6Vendor 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)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| nats-server | 2.10.1-1 ... 2.9.19-1 (15 versions) |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| nats-server | 2.10.27-1 ... 2.14.6-1 (6 versions) |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| nats-server | 2.10.27-1, 2.12.4-1, 2.12.6-1 |
| — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 9× in last 7d / 42× 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 249 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 149 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-11-01 20:03 UTCEG score recompute
- 2026-11-01 20:03 UTCVendor advisory
- 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-25 17:28 UTCEG score recompute
- 2026-10-25 17:28 UTCVendor advisory
- 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-25 14:16 UTCEG score recompute
- 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-23 16:23 UTCEG score recompute
- 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-18 03:28 UTCEG score recompute
- 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-16 13:07 UTCEG score recompute
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- 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-10-12 15:53 UTCEG score recompute
- 2026-10-11 19:36 UTCEG score recompute
- 2026-10-11 16:52 UTCEG score recompute
- 2026-10-11 14:14 UTCEG score recompute
- 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-10-01 16:10 UTCEG score recompute
- 2026-10-01 16:10 UTCVendor advisory
- 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-09-28 13:21 UTCEG score recompute
- 2026-09-28 13:21 UTCVendor advisory
- 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.4% · 27th percentile
- 2026-09-24 11:47 UTCEG score recompute
- 2026-09-24 11:47 UTCVendor advisory
- 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-09-23 06:07 UTCEG score recompute
- 2026-09-23 06:07 UTCVendor advisory
- 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-09-18 05:43 UTCEG score recompute
- 2026-09-18 05:43 UTCVendor advisory
- 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-09-14 11:15 UTCVendor advisory
- 2026-09-13 23:49 UTCEG score recompute
- 2026-09-13 23:49 UTCVendor advisory
- 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-09-13 08:24 UTCEG score recompute
- 2026-09-13 08:24 UTCVendor advisory
- 2026-09-12 14:34 UTCVendor advisory
- 2026-09-12 03:31 UTCEG score recompute
- 2026-09-12 03:31 UTCVendor advisory
- 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-09-06 14:02 UTCEG score recompute
- 2026-09-06 14:02 UTCVendor advisory
- 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-09-05 22:47 UTCEG score recompute
- 2026-09-05 22:47 UTCVendor advisory
- 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-30 18:32 UTCVendor advisory
- 2026-08-30 07:29 UTCEG score recompute
- 2026-08-30 07:29 UTCVendor advisory
- 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-28 21:42 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-27 21:49 UTCEG score recompute
- 2026-08-27 21:49 UTCVendor advisory
- 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-27 01:26 UTCEG score recompute
- 2026-08-27 01:26 UTCVendor advisory
Related CVEs(same product + same CWE)
Same product
10 shownDebian:12:nats-server
Frequently asked(5)
What is CVE-2026-58253?
When was the CVE record for CVE-2026-58253 published?
Is CVE-2026-58253 actively exploited?
What is the CVSS score of CVE-2026-58253?
How do I remediate CVE-2026-58253?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-58253
Is Your Infrastructure Affected by CVE-2026-58253?
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