CVE-2024-22640Public exploit

Service interruption via catastrophic color-regex backtracking

Published Apr 19, 2024 · Updated Nov 4, 2025

Regular expression denial of service in Tecnick.com LTD TCPDF 6.7.4 and earlier allows attackers to consume CPU via crafted HTML colors. TCPDF_COLORS::convertHTMLColorToDec applies a backtracking-prone preg_match expression to numeric fields in JavaScript-style color arrays. An application must pass attacker-controlled HTML into TCPDF's parser; a matching payload exhausts regex work and interrupts PDF generation.

CVSS severity5.1
Medium
EPSS probability1.32%
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 Tecnick.com LTD TCPDF 6.7.4 and earlier allows attackers to consume CPU via crafted HTML colors. TCPDF_COLORS::convertHTMLColorToDec applies a backtracking-prone preg_match expression to numeric fields in JavaScript-style color arrays. An application must pass attacker-controlled HTML into TCPDF's parser; a matching payload exhausts regex work and interrupts PDF generation.

The record

CVE
CVE-2024-22640
Published
Apr 19, 2024
Updated
Nov 4, 2025
Vendor
Tecnick.com LTD
Product
TCPDF
Classifications
CWE-1333, T1499.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 19, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 4, 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?

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  1. Affected versionversion=*

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Tecnick.com LTD · TCPDFversion=*

Published CVSS scores

5.1GitHub Advisory DatabaseCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

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)
Vectorlocal
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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