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Vulnerability · Published Sep 23, 2026 · Assigned by GitHub_M

CVE-2026-59990Jawn: Uncontrolled nesting depth in JSON parser

High 7.5

In plain English

A high-severity resource allocation without limits in jawn from typelevel. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 50% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.6%top 50.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

Jawn is an open source JSON parser. Prior to 1.7.0, Jawn parse methods accept arbitrarily deep JSON array and object nesting without a depth limit, allowing a remote attacker who can submit untrusted JSON to grow parser contexts until the JVM heap is exhausted. The resulting java.lang.OutOfMemoryError is a fatal Scala error that is not ordinarily handled by scala.util.Try or cats.effect.IO, causing denial of service. This issue is fixed in version 1.7.0.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12jawnno fix listedDEBIAN-CVE-2026-59990
Debian:13jawnno fix listedDEBIAN-CVE-2026-59990
Debian:14jawnno fix listedDEBIAN-CVE-2026-59990
Mavenorg.typelevel:jawn-parser_2.121.7.0GHSA-cc4v-rvgp-2pf3
Mavenorg.typelevel:jawn-parser_2.131.7.0GHSA-cc4v-rvgp-2pf3
Mavenorg.typelevel:jawn-parser_31.7.0GHSA-cc4v-rvgp-2pf3
Ubuntu:22.04:LTSjawnno fix listedUBUNTU-CVE-2026-59990
Ubuntu:24.04:LTSjawnno fix listedUBUNTU-CVE-2026-59990
Ubuntu:26.04:LTSjawnno fix listedUBUNTU-CVE-2026-59990
Ubuntu:26.10jawnno fix listedUBUNTU-CVE-2026-59990

Affected products (as reported)

VendorProductVersions
typelevel jawn < 1.7.0

Weakness: CWE-770 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References