CVE-2021-3822Network attack vector

Service hang via getInnerText regex backtracking

Published Sep 27, 2021 · Updated Aug 3, 2024

Regular expression denial of service in JSON Editor before 9.5.6 allows remote attackers to consume excessive CPU via crafted DOM text. The getInnerText function applies an ambiguous whitespace-and-newline regex to attacker-controlled nodeValue text, causing excessive backtracking. Reachability depends on an embedding application passing attacker-controlled DOM elements to this function; the bounded consequence is a service hang from CPU exhaustion.

CVSS severity5.3
Medium
EPSS probability1.42%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Regular expression denial of service in JSON Editor before 9.5.6 allows remote attackers to consume excessive CPU via crafted DOM text. The getInnerText function applies an ambiguous whitespace-and-newline regex to attacker-controlled nodeValue text, causing excessive backtracking. Reachability depends on an embedding application passing attacker-controlled DOM elements to this function; the bounded consequence is a service hang from CPU exhaustion.

The record

CVE
CVE-2021-3822
Published
Sep 27, 2021
Updated
Aug 3, 2024
Vendor
Jos de Jong
Product
JSON Editor
Classifications
CWE-1333, CWE-400, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 27, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record 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=unspecified <9.5.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Jos de Jong · JSON Editorversion=unspecified <9.5.6

Published CVSS scores

5.3huntr.devCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NIST NVDAV: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-1333Inefficient Regular Expression Complexity
CWE-400Uncontrolled Resource Consumption
T1499.004Endpoint Denial of Service: Application or System Exploitation

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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