CVE-2026-58253NATS Server: Route API Auth Bypass
- 8.8HighCVSS base score
- 0.37%Exploitation in 30 daysEPSS · top 69% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By GitHub_M
- 9 days later
· 9 days later
Published
- 1 day later
· 1 day later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High8.8 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L |
| NVDNVD · Analyzed | 3.1 | High8.8 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L |
- EPSS (exploitation in 30 days)
- 0.37% · top 69% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.8.
Affected products
- affected < 2.11.16
- affected >= 2.12.0-preview.1, < 2.12.6
References
References7
- https://github.com/nats-io/nats-server/security/advisories/GHSA-38x3-76xf-cq45 (opens in a new tab)x_refsource_CONFIRM
- https://github.com/nats-io/nats-server/commit/7b81dd455ea95960090a84858c7662827948d1b6 (opens in a new tab)x_refsource_MISC
- https://github.com/nats-io/nats-server/commit/8b8e1ad4ceed32321e00d4fc6e76be05bc13bca6 (opens in a new tab)x_refsource_MISC
- https://github.com/nats-io/nats-server/commit/b86147e81710a52b72a7f7275f91d69f723f5cb3 (opens in a new tab)x_refsource_MISC
- https://github.com/nats-io/nats-server/releases/tag/v2.11.16 (opens in a new tab)x_refsource_MISC
- https://github.com/nats-io/nats-server/releases/tag/v2.12.7 (opens in a new tab)x_refsource_MISC
- https://github.com/nats-io/nats-server/releases/tag/v2.14.0 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-42375 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-58253)Record last updated .