CVSS 3.0
7.2 highCVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:HCVE-2019-12831
High (7.2) in mybb mybb. EPSS 1.5% chance of exploitation in the next 30 days.
In MyBB before 1.8.21, an attacker can abuse a default behavior of MySQL on many systems (that leads to truncation of strings that are too long for a database column) to create a PHP shell in the cache directory of a targeted forum via a crafted XML import, as demonstrated by truncation of aaaaaaaaaaaaaaaaaaaaaaaaaa.php.css to aaaaaaaaaaaaaaaaaaaaaaaaaa.php with a 30-character limit, aka theme import stylesheet name RCE.
Severity
- EPSS
- 1.5% chance of exploitation in the next 30 days; higher than 73% of CVEs (scores of 2026-10-31)
- CWE
- CWE-20
- Published
- Modified
- Record from
- the NVD, synced
Affected
- mybb:mybb