CVE-2023-40599Network attack vector

Service interruption via inefficient add-on regex matching

Published Aug 25, 2023 · Updated Oct 2, 2024

Regular expression denial of service in Mailform Pro CGI 4.3.1.3 and earlier allows remote attackers to interrupt service. Six optional add-ons perform inefficient regular-expression matching, but the vendor has not disclosed the patterns or request fields involved. Unauthenticated exposure requires at least one affected add-on to be enabled, and the documented consequence is service interruption only.

CVSS severity3.7
Low
EPSS probability0.89%
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 Mailform Pro CGI 4.3.1.3 and earlier allows remote attackers to interrupt service. Six optional add-ons perform inefficient regular-expression matching, but the vendor has not disclosed the patterns or request fields involved. Unauthenticated exposure requires at least one affected add-on to be enabled, and the documented consequence is service interruption only.

The record

CVE
CVE-2023-40599
Published
Aug 25, 2023
Updated
Oct 2, 2024
Vendor
SYNCK GRAPHICA
Product
Mailform Pro CGI
Classifications
CWE-1333, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 25, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 2, 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=4.3.1.3 and earlier

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

SYNCK GRAPHICA · Mailform Pro CGIversion=4.3.1.3 and earlier

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.7JPCERT/CCCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
4.3JPCERT/CCAV:N/AC:M/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-1333Inefficient Regular Expression Complexity
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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