Washington (CNN) -- The Transportation Security Administration is failing to adequately report, track and fix airport security breaches, according to the Department of Homeland Security's inspector general.
As a result, the TSA "does not have a complete understanding" of breaches at the nation's airports, says a report from the inspector general.
Congress will hold a hearing on the inspector general's report Wednesday.
The report, published earlier this month, was requested by New Jersey Democratic Sen. Frank Lautenberg after a series of breaches at Newark Airport, including a knife bypassing TSA screening, passengers walking around security checkpoints and a dead dog transported without being screened for explosives.
TSA responded to those incidents with "corrective action," according to the inspector general, but not all the problems received the same treatment.
The TSA took action to fix only 42% of the security breaches documented at Newark Airport, according to the report.
Most of the incidents examined occurred in 2010, and the report says since then efforts to fix security breach vulnerabilities have improved.
Five other large U.S. terminals were visited by inspectors for comparison but the airports' names were withheld from the public report.
Of the six airports visited, records were found detailing efforts to fix the causes of only 53% of the breaches.
Newark was the lowest-scoring. The highest-rated airport reported corrective action in 88% of the breaches.
The inspector general also noted that while the agency did have "many programs and initiatives that report and track identified security breaches" they were "not all inclusive or centrally managed."
This lack of comprehensive, centralized data was cited as preventing the use of information to "monitor trends or make general improvements to security."
Problems with how incidents were categorized in reporting also were outlined in the report.
TSA workers at one airport reported "an improper bag handoff incident" in a database as a "sterile area access event" while another airport reported four similar incidents as "security breaches."
Management at the agency concurred with the inspector general's report.
"TSA acknowledges that it can further develop and expand its oversight programs for gathering and tracking airport security breaches," wrote administrator John Pistole.
"TSA currently collects thousands of records of incidents and security breaches occurring at airports and other transportation facilities," TSA spokesman David Castelveter told CNN in an e-mail. "TSA is coordinating appropriate revisions to relevant Operations Directives to develop a single definition of 'Security Breach,' addressing (the inspector general's) recommendation."
CNN's Lizzie O'Leary contributed to this report.