Renowned privacy-centric cryptocurrency, PIVX has temporarily disabled zPIV. The team first made the disclosure on their official Discord channel on March 7, stating that:

zPIV functionality has been temporarily disabled while we investigate a potential issue.

Details of the issue are yet to be revealed. However, the PIVX team has assured users that their coins are safe and their privacy has not been compromised in any way. Confirming this in a tweet, they noted that:

An in-depth vulnerability report written by the core development team along with the PR in GitHub will be published soon outlining all the details of the recently detected Zerocoin zPIV issue and the fix. Rest assured, it does not affect your coins nor their privacy.

The much we know is that the potential issue affects only custom Zerocoin implementation. As such, all PIVX forks have been advised to disable Zerocoin via spork and wait until a patch is released.

zPIV provides a protocol-level coin mixing service using zero-knowledge proofs to sever the link between the sender and the receiver with 100% anonymity and un-traceability. The use of zPIV also means your balance can be masked to avoid being targeted by potential thieves. This is a very unique feature that nearly no other cryptocurrency currently in the market possesses.