What is CVE-2021-23126?

CVE-2021-23126 is a medium-severity vulnerability in Joomla Joomla\!, classified under Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG). CVSS score: 5.3/10. Published 2021-03-04.

How severe is CVE-2021-23126?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Vulnerability in Joomla Joomla\!

CVE-2021-23126

An issue was discovered in Joomla! 3.2.0 through 3.9.24. Usage of the insecure rand() function within the process of generating the 2FA secret.

Published 2021-03-04 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.011 (64.6th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 65th percentile — 64.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: +0.000

Affected products

Joomla Joomla\!
Joomla! Project Cms — versions 3.2.0-3.9.24

Weakness classification (CWE)

CWE-338 — Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

References

developer.joomla.org/security-centre/841-20210301-core-insecure-randomness-with… (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2021-23126?: CVE-2021-23126 is a medium-severity vulnerability in Joomla Joomla\!, classified under Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG). CVSS score: 5.3/10. Published 2021-03-04.
How severe is CVE-2021-23126?: Medium severity. CVSS v3 base score is 5.3 out of 10.