The rescheduling was prompted as billionaire investor Carl Icahn upped his ante against Yang in view of the revelations that came on Monday when a Delaware judge unsealed court documents in a lawsuit filed by shareholders.
The annual shareholders meeting originally slated for July 3, has been rescheduled for the third time on August 1.
The meeting will see shareholders voting on whether to re-elect Yahoo's current directors or replace them with Icahn-proposed alternate slate of directors.
Icahn, angered by Yahoo's rejection of Microsoft acquisition offer and the latest revelations, indicated in an interview to The Wall street Journal that he planned to wrest control of the board and return the company to the bargaining table.
Although the Yahoo board of directors includes Yang, Icahn had not in the past spoken about removing him as the CEO.
On Monday, a Delaware judge unsealed court documents that revealed how Yahoo schemed well in advance to make the acquisition more expensive for the Microsoft.
The details tumbled out of previously sealed records obtained as part of a shareholder lawsuit alleging Yahoo board of improperly resisting Microsoft's acquisition bid. The lawsuit alleges that CEO Yang was so determined to keep Yahoo independent that he devised a beefed up employee severance plan that would have significantly increased the cost of acquisition.