NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.14 and 2.12.5, if the nats-server has the "leafnode" configuration enabled (not default), then anyone who can connect can crash the nats-server by triggering a panic. This happens pre-authentication and requires that compression be enabled (which it is, by default, when leafnodes are used). Versions 2.11.14 and 2.12.5 contain a fix. As a workaround, disable compression on the leafnode port.
CVE-2026-29785
HIGHPre-NVD 7.57.5
EchelonGraph scoreLOW confidence
This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: secondary
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 7.5Exploit: NoneExposed: 0
A fix is available — apply it.
- CVSS v3
- 7.5
- EG Score
- 7.5(low)
- EPSS
- 47.0%
- KEV
- Not listed
Published
March 25, 2026
Last Modified
June 30, 2026
Advisory Details (9)
Auto-updated Jul 3, 2026Patch available. Sources: github_commit, github, redhat.
redhat Patch Available
redhat
2451444 – (CVE-2026-29785) CVE-2026-29785 github.com/nats-io/nats-server: NATS-Server: Denial of Service via leafnode compression
https://bugzilla.redhat.com/show_bug.cgi?id=2451444redhat Patch Available
redhat Patch Available
redhat Patch Available
github Patch Available
leafnode pre-auth server panic DoS · Advisory · nats-io/nats-server · GitHub
https://github.com/nats-io/nats-server/security/advisories/GHSA-52jh-2xxh-pwh6github_commit
commit a1488de6f2ba (nats-io/nats-server)
Fix landed in nats-io/nats-server commit a1488de6f2ba — awaiting tagged release
https://github.com/nats-io/nats-server/commit/a1488de6f2ba6e666aef0f9cce0016f7f167d6a8Vendor Advisories for CVE-2026-29785(4)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2026:23345Red Hat Product SecurityHigh
Red Hat Security Advisory: Multicluster Global Hub 1.6.2 security update
- RHSA-2026:22347Red Hat Product SecurityHigh
Red Hat Security Advisory: Multicluster Global Hub 1.4.5 security update
- CVE-2026-29785Microsoft Security Response Center (MSRC)High
NATS Server panic via malicious compression on leafnode port
- RHSA-2026:21769Red Hat Product SecurityHigh
Red Hat Security Advisory: Multicluster Global Hub 1.5.4 security update
Patch Availability(3)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| redhat | multicluster-globalhub/multicluster-globalhub-grafana-rhel9:1780167118 | 2026-06-04 | redhat |
| redhat | multicluster-globalhub/multicluster-globalhub-grafana-rhel9:1779579439 | 2026-06-01 | redhat |
| redhat | multicluster-globalhub/multicluster-globalhub-grafana-rhel9:1778867753 | 2026-05-28 | redhat |
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
(2 across 1 ecosystem)
Go(2)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| github.com/nats-io/nats-server | — | — | — |
| github.com/nats-io/nats-server/v2 | — | 2.11.14 | — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 8× in last 7d / 11× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-05 02:30 UTCEPSS rescore
- 2026-07-04 06:31 UTCEPSS rescore
- 2026-07-01 15:06 UTCEPSS rescore
- 2026-06-30 23:22 UTCEPSS rescore
- 2026-06-30 04:37 UTCEG score recompute
- 2026-06-30 04:37 UTCVendor advisory
- 2026-06-30 04:32 UTCNVD updatefirst tracked
Related CVEs(same vendor + same CWE)
Same vendor
10 shownmsrc · redhat
Frequently asked(5)
What is CVE-2026-29785?
CVE-2026-29785 is a high vulnerability published on March 25, 2026. NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.14 and 2.12.5, if the nats-server has the "leafnode" configuration enabled (not default), then anyone who can connect can crash the nats-server by triggering a panic. This happens…
When was CVE-2026-29785 disclosed?
CVE-2026-29785 was first published in the National Vulnerability Database on March 25, 2026, with the most recent update on June 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-29785 actively exploited?
CVE-2026-29785 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 47.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-29785?
CVE-2026-29785 has a CVSS v3 base score of 7.5 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-29785?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-29785, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-29785
Is Your Infrastructure Affected by CVE-2026-29785?
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