CVE-2018-18531
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.47%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.0
- 9.8 CRITICALCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 1.47% probability · 74th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-330
- Affected
- kaptcha project/kaptcha
- Source
- cve@mitre.org
EPSS 1.5% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/penggle/kaptcha/issues/3Third Party Advisory
- https://github.com/penggle/kaptcha/issues/3Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.