The analyzer has detected an expression of the 'T foo = foo = X' pattern. The variable being initialized is itself taking part in the assignment. Unlike the issue diagnosed by the V593 rule, the foo variable here is initialized by an X expression; however, this code is very suspicious: the programmer should have most likely meant something else.
Here is an example of incorrect code:
int a = a = 3;
It's hard to say for sure what was actually meant here. Probably the correct code should look as follows:
int a = 3;
It is also possible that the programmer wanted to initialize the variable through assigning a value to another variable:
int a = b = 3;
According to Common Weakness Enumeration, potential errors found by using this diagnostic are classified as CWE-480.
You can look at examples of errors detected by the V700 diagnostic.