- Backdrop Core 1.21.x versions prior to 1.21.2
- Backdrop Core 1.20.x versions prior to 1.20.5
Backdrop versions 1.19 and prior do not receive security coverage.
Backdrop core's Form API has a vulnerability where certain forms in contributed or custom modules may be vulnerable to improper input validation. This could allow an attacker to inject disallowed values or overwrite data. Affected forms are uncommon, but in certain cases an attacker could alter critical or sensitive data.