{"id":"JLSEC-2026-1132","details":"NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.15 and 2.12.6, when using mTLS for client identity, with `verify_and_map` to derive a NATS identity from the client certificate's Subject DN, certain patterns of RDN would not be correctly enforced, allowing for authentication bypass. This does require a valid certificate from a CA already trusted for client certificates, and `DN` naming patterns which the NATS maintainers consider highly unlikely. So this is an unlikely attack. Nonetheless, administrators who have been very sophisticated in their `DN` construction patterns might conceivably be impacted. Versions 2.11.15 and 2.12.6 contain a fix. As a workaround, developers should review their CA issuing practices.","modified":"2026-08-03T19:15:05.110587493Z","published":"2026-08-03T19:08:57.739Z","upstream":["CVE-2026-33248"],"database_specific":{"sources":[{"modified":"2026-06-17T10:37:11.377Z","published":"2026-03-25T21:16:47.563Z","url":"https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-33248","html_url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33248","database_specific":{"status":"Analyzed"},"id":"CVE-2026-33248","imported":"2026-08-03T18:16:27.374Z"}],"license":"CC-BY-4.0"},"references":[{"type":"WEB","url":"https://advisories.nats.io/CVE/secnote-2026-13.txt"},{"type":"WEB","url":"https://github.com/nats-io/nats-server/security/advisories/GHSA-3f24-pcvm-5jqc"}],"affected":[{"package":{"name":"nats_server_jll","ecosystem":"Julia","purl":"pkg:julia/nats_server_jll?uuid=8b1691f7-6002-537d-bdf7-c6203599dc08"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"2.14.3+0"}]}],"database_specific":{"source":"https://github.com/JuliaLang/SecurityAdvisories.jl/tree/generated/osv/2026/JLSEC-2026-1132.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N"}]}