According to the report by GOP members of five House committees, senior State Department officials including Clinton approved reductions in security at the facility. The report points to an April 2012 cable with Clinton's signature acknowledging a March 2012 request from then-U.S. Ambassador to Libya Gene Cretz for more security, yet allowing further reductions.
"Senior State Department officials knew that the threat environment in Benghazi was high and that the Benghazi compound was vulnerable and unable to withstand an attack, yet the department continued to systematically withdraw security personnel," the report said.
White House spokeswoman Caitlin Hayden says the GOP report "appears to raise questions that have already been asked and answered in great detail" by Obama administration officials.
Clinton testified before Congress and took responsibility for the department's missteps, but insisted a request for more security never reached her desk.
During congressional testimony in January, Clinton rejected the notion that a secretary of state sees every cable addressed to them.
The report also criticized President Barack Obama and the White House staff's actions in the days following the attack, saying accurate "talking points" were altered.
These talking points cost Susan Rice, the U.S. ambassador to the United Nations, an opportunity to replace Clinton as secretary of state. Less than a week after the attack, Rice used the talking points to say on a series of talk show interviews that the raid may have been a protest that got out of hand. Republicans blasted Rice over her initial comments about the attacks and she later asked for her name to be removed from consideration to head the State Department.
The top Democrats on the five committees criticized the GOP report, telling House Speaker John Boehner in a letter Tuesday that they strongly objected to the report, the politicizing of national security and their exclusion from the investigation.
The Democrats called the report "partisan Republican staff report on Benghazi" that dispensed with regular House procedures "for vetting official committee reports to correct inaccuracies and mischaracterizations."
The Associated Press contributed to this report.