Sorry for the delay, but I was having a computer glitch.
If your severance states that the terms and conditions of the severance are confidential, and the former employer discloses those terms, and you are damaged by the disclosure (e.g., demotion, termination, etc.), then you would have a claim for breach of contract, and for the value of the damages, including lost wages until you find new employment.
In addition, you could have a common law claim for interference with contract, or defamation of character, each of which would give you damages in a similar fashion to that of the breach of the severance contract. The difference would be that if your severance contract has a prevailing party attorney's fees clause, then you would be entitled to attorney's fees, which would not be available under a common law claim.
There is also Labor Code 1050 under which an employer cannot, by misrepresentation, prevent a former employee from obtaining employment. Labor Code 1054 permits an aggrieved former employee the right to sue for "treble damages" for the violation of Labor Code 1054 (i.e., three times actual damages).
So, you have a number of options here -- and I encourage you to seek an employment rights lawyer in your area, because you may have a very valuable claim -- depending upon what your current employer decides to do concerning your employment status.
For a competent attorney referral, see this link.
Hope this helps.