She had been accused of planning to broadcast fabricated images.
Taha, who was making a documentary on torture in Egyptian police stations, described the decision as "an unjust, vindictive ruling by the government's judiciary".
She can appeal against the verdict.
In January, she was briefly arrested and her 50 videotapes confiscated at Cairo airport.
Taha, an Egyptian citizen, is currently in Qatar, where al Jazeera's headquarters are situated.
Taha disputed the court's ruling and said that she had obtained the necessary work licences from the Egyptian authorities.
She said: "All the security services concerned were aware of the work I was doing."
Officials from al Jazeera declined to comment on the case.
Rights groups have accused the court of violating internationally recognised fair trial norms, and said that Egypt was guilty of harassing the media.