Updated to add Jim Cramer's comments.

CSX (CSX - Get Report) is reportedly in talks with an activist seeking to overhaul the railroad ahead of a key deadline for investors to nominate candidates to the company's board.

Officials from Jacksonville, Fla.-based CSX met with veteran railroad executive Hunter Harrison and representatives from activist Mantle Ridge over the firm's push for more than three seats on the company's board, according to a report in The Wall Street Journal. Harrison stepped down as CEO of Canadian Pacific (CP) earlier this month to join Mantle Ridge's efforts to shake up CSX.

The report said that while CSX, which was represented at the meeting by board members Edward Kelly and David Ratcliffe, is open to a compromise it is reluctant to surrender that many board seats. The two sides are trying to reach a compromise prior to the Feb. 10 deadline for investors to nominate directors, though that date could be pushed back if the company sees reason to continue talks.

CSX shares have gained more than 20% -- adding about $8 billion in market capitalization - since word of the potential campaign became public earlier this month, with investors hopeful that Harrison would have success streamlining the railroad and making it more efficient. The exec was brought to Canadian Pacific by activist Bill Ackman in 2012 and orchestrated a turnaround there that led to CP's Toronto-based shares to climb nearly 190% during his tenure.

Given his popularity and the stock's reaction to the idea of Harrison taking over CSX could face a difficult struggle convincing investors not to vote for a Mantle Ridge slate, giving the company every reason to try to negotiate a compromise.

But investors need to be careful not to get ahead of themselves. Even if Harrison does end up replacing CSX's long-serving Chief Executive Michael Ward, a turnaround would take time and would be no sure bet. A rail source speaking to TheStreet earlier this month praised Harrison and his partners' acumen, saying, "They've identified an entire industry loaded with inefficiency and see a tremendous opportunity there," but that same source questioned how much time and energy the 72-year-old executive was ready to give to CSX.

"This isn't a short-term project," the source said.

Meanwhile, speaking on CNBC's "Mad Dash" segment Monday, TheStreet's Jim Cramer, co-manager of the Action Alerts PLUS portfolio, said buyers should be cautious on CSX stock, currently at $47.31, down 1.6%.

The idea that Ward, who has been CEO since 2003, would walk away and that a newcomer would take over the helm and suddenly "turn on the jets" doesn't seem plausible, he said. Unless the new CEO were to sell the company, which isn't in the current realm of discussion, there isn't a ton of room to improve at CSX, Cramer explained.

Ward is a good operator, he said. "There's no miracle to running a railroad" and a new CEO will not "suddenly reinvent" the company. In the end, it's just a railroad and, right now, the majors are doing fine, Cramer concluded.