{"cve":"CVE-2026-33246","nvd":{"published":"2026-03-25T20:16:33.010","modified":"2026-06-17T10:37:11.157","status":"Analyzed","description":"NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. The nats-server offers a `Nats-Request-Info:` message header, providing information about a request. This is supposed to provide enough information to allow for account/user identification, such that NATS clients could make their own decisions on how to trust a message, provided that they trust the nats-server as a broker. A leafnode connecting to a nats-server is not fully trusted unless the system account is bridged too. Thus identity claims should not have propagated unchecked. Prior to versions 2.11.15 and 2.12.6, NATS clients relying upon the Nats-Request-Info: header could be spoofed. This does not directly affect the nats-server itself, but the CVSS Confidentiality and Integrity scores are based upon what a hypothetical client might choose to do with this NATS header. Versions 2.11.15 and 2.12.6 contain a fix. No known workarounds are available.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N","score":5.4},"cwes":["CWE-287","CWE-290"],"references":["https://advisories.nats.io/CVE/secnote-2026-08.txt","https://github.com/nats-io/nats-server/security/advisories/GHSA-55h8-8g96-x4hj"],"products":["linuxfoundation:nats-server"],"source":"nvd","synced_at":"2026-10-19T22:28:18.033120106+00:00"},"epss":{"cve":"CVE-2026-33246","score":0.00149,"percentile":0.0404,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-55h8-8g96-x4hj","url":"https://osv.dev/vulnerability/GHSA-55h8-8g96-x4hj","summary":"NATS: Leafnode connections allow spoofing of Nats-Request-Info identity headers","modified":"2026-09-10T03:50:59.829737231Z","packages":[{"ecosystem":"Go","name":"github.com/nats-io/nats-server/v2","purl":"pkg:golang/github.com/nats-io/nats-server/v2","ranges":["<2.11.15"],"fixed":["2.11.15"]},{"ecosystem":"Go","name":"github.com/nats-io/nats-server/v2","purl":"pkg:golang/github.com/nats-io/nats-server/v2","ranges":[">=2.12.0-RC.1 <2.12.6"],"fixed":["2.12.6"]},{"ecosystem":"Go","name":"github.com/nats-io/nats-server","purl":"pkg:golang/github.com/nats-io/nats-server","ranges":["all versions"],"fixed":[]}]},{"id":"GO-2026-4830","url":"https://osv.dev/vulnerability/GO-2026-4830","summary":"NATS: Leafnode connections allow spoofing of Nats-Request-Info identity headers in github.com/nats-io/nats-server","modified":"2026-03-27T18:26:07.658196Z","packages":[{"ecosystem":"Go","name":"github.com/nats-io/nats-server","purl":"pkg:golang/github.com/nats-io/nats-server","ranges":["all versions"],"fixed":[]},{"ecosystem":"Go","name":"github.com/nats-io/nats-server/v2","purl":"pkg:golang/github.com/nats-io/nats-server/v2","ranges":["<2.11.15",">=2.12.0-RC.1 <2.12.6"],"fixed":["2.11.15","2.12.6"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}