The security breaches, averaging about seven a day since November 2001, let more than 14,000 people enter "limited-access" areas by going through airport doors or passageways without permission, U.S. Transportation Security Administration statistics indicated.
The breaches also let unauthorized people go from airport buildings to planes, the report found.
The information, first reported by USA Today, was to be presented to the House national security subcommittee Wednesday.
It also included 6,000 breaches when TSA screeners failed to screen, or improperly screened, passengers or carry-on items, the statistics indicated.
TSA spokesman Nicholas Kimball said the breaches represented a tiny fraction of 1 percent of the 5.5 billion flyers using U.S. airports since 2001.
"Breach" is also defined broadly and can mean accidental violations that pose no real public danger, he said.
Security consultant Raffi Ron, a former security director at Tel Aviv's Ben-Gurion International Airport, is expected to testify Wednesday TSA's focus on screening passengers and bags have relegated other security aspects "to the back seat," USA Today reported, citing testimony submitted to the House subcommittee.
Ron's testimony was to take place while another House subcommittee reviewed a Government Accountability Office report indicating many U.S. airports' explosives-screening equipment used detection criteria dating before the Sept. 11, 2001, terrorist attacks.
Even explosive-detection systems installed now are out of date and will require upgrading before they can meet the latest 2010 standards, the GAO report released Tuesday said.
Many machines -- which use CAT scans and sophisticated image processing software to screen checked baggage for explosives -- still operate under 1998 standards, the report said.
The standards were revised by TSA in 2005 and then in January 2010 after the Dec. 25, 2009, attempt to bomb a Detroit-bound airliner using explosives hidden in a passenger's underwear.
The report by the GAO -- Congress' audit, evaluation and investigative arm -- said machines installed this year still used the 2005 standards and might need multiple software and hardware upgrades to become current, The Washington Times reported.
Kimball said in a statement the standard used by most U.S. airports' explosive-detection system units provided "the most stringent level of checked baggage security in the world."
"All new EDS units purchased by TSA and technologies currently undergoing lab testing allow TSA to upgrade the software to meet revised standards without replacing the physical equipment," his statement said. "New EDS units purchased by TSA and technologies undergoing lab testing meet the 2010 standard."
The upgrades to meet 2010 standards were one of six GAO recommendations TSA said it was implementing.