Servers and applications
CVE-2013-6386 Drupal 6.x before 6.29 and 7.x before 7.24 uses the PHP mt_rand function to generate random numbers, which uses predictable seeds and allows remote attackers to predict security strings and bypass intended restrictions via a brute force attack.
Severity Medium 6.8
Published 7 Dec 2013
Last changed 17 Jun 2026
Added to UpHeron 1 Nov 2026 Exploit chance 2.1% in the next 30 daysHigher than 81% of CVEs. EPSS by FIRST , 12 Nov 2026
Attack Over the network · No login needed
Attacker can Read some data · Change some data · Slow it down
CVSS vector AV:N/AC:M/Au:N/C:P/I:P/A:P
Sources NVD Affected software Software Affected versions DrupalServers and applications · cpe:a:drupal:drupal Version 7.23 Version 7.22 Version 7.21 Version 7.20 All 78 release lines Version 6.0-dev Version 6.0-beta1 Version 6.0-beta2 Version 6.0-beta3 Version 6.0-beta4 Version 6.0-rc1 Version 6.0-rc2 Version 6.0-rc3 Version 6.0-rc4 Version 6.0 Version 6.1 Version 6.2 Version 6.3 Version 6.4 Version 6.5 Version 6.6 Version 6.7 Version 6.8 Version 6.9 Version 6.10 Version 6.11 Version 6.12 Version 6.13 Version 6.14 Version 6.15 Version 6.16 Version 6.17 Version 6.18 Version 6.19 Version 6.20 Version 6.21 Version 6.22 Version 6.23 Version 6.24 Version 6.25 Version 6.26 Version 6.27 Version 6.28 Version 7.0-dev Version 7.0-alpha1 Version 7.0-alpha2 Version 7.0-alpha3 Version 7.0-alpha4 Version 7.0-alpha5 Version 7.0-alpha6 Version 7.0-alpha7 Version 7.0-beta1 Version 7.0-beta2 Version 7.0-beta3 Version 7.0-rc1 Version 7.0-rc2 Version 7.0-rc3 Version 7.0-rc4 Version 7.x-dev Version 7.0 Version 7.1 Version 7.2 Version 7.3 Version 7.4 Version 7.5 Version 7.6 Version 7.7 Version 7.8 Version 7.9 Version 7.10 Version 7.11 Version 7.12 Version 7.13 Version 7.14 Version 7.15 Version 7.16 Version 7.17 Version 7.18 Version 7.19 Version 7.20 Version 7.21 Version 7.22 Version 7.23
References NVD https://nvd.nist.gov/vuln/detail/CVE-2013-6386 CVE.org https://www.cve.org/CVERecord?id=CVE-2013-6386