CVE-2023-39619Public exploitNetwork attack vector

Application hang via inefficient email regex

Published Oct 24, 2023 · Updated Sep 11, 2024

Regular expression denial of service in node-email-check 1.0.4 and earlier allows remote attackers to hang a consuming application. The isValidSync function applies the scpSyntax regular expression to a crafted email string with inefficient worst-case matching that consumes excessive CPU time. No privileges or user interaction are required when an application exposes email validation to untrusted network input, and the demonstrated consequence is an application hang.

CVSS severity7.5
High
EPSS probability1.08%
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 node-email-check 1.0.4 and earlier allows remote attackers to hang a consuming application. The isValidSync function applies the scpSyntax regular expression to a crafted email string with inefficient worst-case matching that consumes excessive CPU time. No privileges or user interaction are required when an application exposes email validation to untrusted network input, and the demonstrated consequence is an application hang.

The record

CVE
CVE-2023-39619
Published
Oct 24, 2023
Updated
Sep 11, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-1333, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 24, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-1333Inefficient Regular Expression Complexity
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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