CVE-2022-21653Network attack vector

Service interruption via collision-prone object maps

Published Jan 5, 2022 · Updated Apr 22, 2025

Hash-collision resource exhaustion in Jawn before 1.3.2 allows remote attackers to interrupt services with crafted JSON objects. The default objectContext() implementations in SimpleFacade and MutableFacade build Scala hash-trie maps whose colliding keys degrade insertion efficiency and exhaust resources. Exposure requires an application to inherit either facade without overriding objectContext() and to parse attacker-controlled JSON; the bounded impact is service interruption.

CVSS severity5.9
Medium
EPSS probability0.79%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Hash-collision resource exhaustion in Jawn before 1.3.2 allows remote attackers to interrupt services with crafted JSON objects. The default objectContext() implementations in SimpleFacade and MutableFacade build Scala hash-trie maps whose colliding keys degrade insertion efficiency and exhaust resources. Exposure requires an application to inherit either facade without overriding objectContext() and to parse attacker-controlled JSON; the bounded impact is service interruption.

The record

CVE
CVE-2022-21653
Published
Jan 5, 2022
Updated
Apr 22, 2025
Vendor
MVP Themes
Product
Jawn
Classifications
CWE-400, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 5, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 22, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.3.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

MVP Themes · Jawnversion=< 1.3.2

Published CVSS scores

5.9GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5NISTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NISTAV:N/AC:L/Au:N/C:N/I:N/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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