Is CVE-2018-18531 actively exploited?

No active exploitation of CVE-2018-18531 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2018-18531 be exploited remotely?

Yes. CVE-2018-18531 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2018-18531?

CVE-2018-18531 has a CVSS score of 9.8 (CRITICAL).

HOME VULNERABILITIESCVE-2018-18531

CRITICAL

CVE-2018-18531

CWE-330Published: October 19, 2018· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

text/impl/DefaultTextCreator.java, text/impl/ChineseTextProducer.java, and text/impl/FiveLetterFirstNameTextCreator.java in kaptcha 2.3.2 use the Random (rather than SecureRandom) function for generating CAPTCHA values, which makes it easier for remote attackers to bypass intended access restrictions via a brute-force approach.

NVD Source

Technical Analysis

CVE-2018-18531 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.