Senior CBS correspondent Lara Logan is recovering in hospital in the US after she was beaten and sexually assaulted by a mob while covering the Egyptian protests, the US network says.
It says the attack occurred on Friday in Cairo's packed Tahrir Square after President Hosni Mubarak stepped down.
Ms Logan became separated from her crew and was rescued by women and soldiers.
The Committee to Protect Journalists has said 52 journalists were assaulted and 76 detained during events in Egypt.
The New York-based group said all of them had since been released.
In a statement, CBS said that Ms Logan and her team became "surrounded by a dangerous element amidst the celebration" with a mob of more than 200 people "whipped into a frenzy".
It said Ms Logan was recovering following what it described as "a brutal and sustained sexual assault and beating".
A group of women and an estimated 20 soldiers managed to save her after she became separated from her colleagues and security, it added.
The 39-year-old South African returned to the US on Saturday.
Ms Logan is CBS News' chief foreign affairs correspondent and has reported from Iraq and Afghanistan.
The Committee to Protect Journalists (CPJ) said the attack was "alarming", describing Ms Logan as a "brilliant, courageous, and committed reporter".
In its annual report issued on Tuesday, the CPJ said Pakistan was the deadliest country for journalists in 2010, with 8 killed while doing their job, out of 44 worldwide.
The number of jailed reporters was 145, an increase from previous years.