{"id":"CVE-2026-59990","aliases":["GHSA-cc4v-rvgp-2pf3"],"url":"https://o3.security/vulnerability/CVE-2026-59990","summary":"Jawn: Uncontrolled nesting depth in JSON parser","details":"The Jawn parser before 1.6.1 is vulnerable to a denial of service attack via untrusted input.\n\n### Impact\n\nA remote attacker who can submit JSON to any jawn-backed parse method can exhaust JVM heap and trigger `java.lang.OutOfMemoryError`.  This is treated by Scala as a fatal error and not typically handled by `scala.util.Try` or `cats.effect.IO`.\n\n### Patches\n\nVersion `1.6.1` introduces a configurable nesting-depth limit (`Parser#maxDepth`, default `4096`).  Inputs deeper than the limit fail with a recoverable `ParseException` instead of exhausting heap.\n\nUsers who require deeper nesting may override `maxDepth` on a `Parser` subclass.\n\n### Workarounds\n\n- Enforce an input size limit small enough that the resulting context stack cannot exhaust heap, (e.g. http4s `EntityLimiter`).\n- Pre-scan untrusted input and reject documents whose maximum delimiter nesting exceeds a threshold before handing them to jawn.","published":"2026-09-23T18:41:12.073Z","modified":"2026-10-21T02:58:50.494342957Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Maven","name":"org.typelevel:jawn-parser_2.12","fixedVersion":"1.7.0"},{"ecosystem":"Maven","name":"org.typelevel:jawn-parser_2.13","fixedVersion":"1.7.0"},{"ecosystem":"Maven","name":"org.typelevel:jawn-parser_3","fixedVersion":"1.7.0"}],"fix":{"url":"https://github.com/typelevel/jawn/commit/191cb3a44e77f1afab439ee636bf66bdf3c54a04","label":"typelevel/jawn@191cb3a"},"references":[{"type":"WEB","url":"https://github.com/typelevel/jawn/releases/tag/v1.7.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59990.json"},{"type":"ADVISORY","url":"https://github.com/typelevel/jawn/security/advisories/GHSA-cc4v-rvgp-2pf3"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59990"},{"type":"FIX","url":"https://github.com/typelevel/jawn/commit/191cb3a44e77f1afab439ee636bf66bdf3c54a04"},{"type":"FIX","url":"https://github.com/typelevel/jawn/commit/6219666641f9408498f85868f835e17bd8a72fed"},{"type":"FIX","url":"https://github.com/typelevel/jawn/commit/93ac93e9c992c11b4c03d5455d8551f9fb24da1b"},{"type":"FIX","url":"https://github.com/typelevel/jawn/commit/f6ace7e0db715de1a8c4618bed9378333a5c2214"},{"type":"PACKAGE","url":"https://github.com/typelevel/jawn"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-21T02:58:50.494342957Z"}}