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

> Remote attackers can cause denial of service in applications using Jawn by submitting deeply nested JSON, exhausting JVM memory.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 23 Sep 2026
- **Updated:** 23 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-59990, GHSA-cc4v-rvgp-2pf3, UBUNTU-CVE-2026-59990

## What is CVE-2026-59990?

CVE-2026-59990 is a high-severity denial of service vulnerability in typelevel jawn, published on 23 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### 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.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-59990?

6 open source packages ship an affected version, including org.typelevel:jawn-parser_2.12, org.typelevel:jawn-parser_2.13 and org.typelevel:jawn-parser_3.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.typelevel:jawn-parser_2.12` | Maven | All versions | 1.7.0 |
| `org.typelevel:jawn-parser_2.12` | Maven | All versions | 1.7.0 |
| `org.typelevel:jawn-parser_2.13` | Maven | All versions | 1.7.0 |
| `org.typelevel:jawn-parser_2.13` | Maven | All versions | 1.7.0 |
| `org.typelevel:jawn-parser_3` | Maven | All versions | 1.7.0 |
| `org.typelevel:jawn-parser_3` | Maven | All versions | 1.7.0 |

## How do I fix CVE-2026-59990?

Upgrade org.typelevel:jawn-parser_2.12 to 1.7.0 or later.

## Is CVE-2026-59990 being exploited?

There is no known exploitation of CVE-2026-59990 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-59990 and fix it if it is affected.

What it is: CVE-2026-59990 is a high-severity denial of service vulnerability in typelevel jawn, published on 23 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-59990 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.typelevel:jawn-parser_2.12 (Maven): affected all versions; fixed in 1.7.0
- org.typelevel:jawn-parser_2.12 (Maven): affected all versions; fixed in 1.7.0
- org.typelevel:jawn-parser_2.13 (Maven): affected all versions; fixed in 1.7.0
- org.typelevel:jawn-parser_2.13 (Maven): affected all versions; fixed in 1.7.0
- org.typelevel:jawn-parser_3 (Maven): affected all versions; fixed in 1.7.0
- org.typelevel:jawn-parser_3 (Maven): affected all versions; fixed in 1.7.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-59990/ (Markdown: https://insights.sbomify.com/CVE-2026-59990/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-59990
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-59990
- OSV: https://osv.dev/vulnerability/CVE-2026-59990

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-59990/
Summaries are generated and may contain mistakes; the official description above is the record.