Common Mode Rejection Ratio vs Common Mode Voltage
That parameter says nothing about the CMRR. All it is telling you is the maximum common mode voltage (\$V_{comm}\$) the amplifier can handle while still meeting the other specifications.







simulate this circuit &ndash; Schematic created using CircuitLab

$$ V_{comm} = \frac{V_+ + V_-}{2}$$

Provided that \$V_{comm} &lt; 1.2V\$ (and really, they probably mean \$-1.2V &lt; V_{comm} &lt; 1.2V\$) then the amplifier will function according to specifications. Ostensibly, this common mode signal is attenuated, but if the CMRR is unspecified, then we don't know by how much.