The University of Canberra has accidentally sent some staff the personal details of every employee, including their birth date, classification, average hours and salary.
Vice-chancellor Deep Saini said an "administrative error" led to 24 employees receiving the email with searchable data on all their colleagues attached.
The first batch of emails was sent Thursday but the university was unaware of the data breach until Friday afternoon.
At that point, employees who received the information were instructed to delete the email and its attachments, while the university wiped copies of the email from all inboxes and investigated whether anyone had sent the data to people outside the institution.
In a statement to staff sent Monday, Professor Saini said those who received the email had followed the university's directions.
"In light of the steps taken, the university is satisfied that the data breach has been remedied and that there is unlikely to be any significant risk of harm caused to employees as a result of the data breach," he said.
"Our processes and procedures for handling this information are being reviewed to ensure that this does not happen again.
"The university is also notifying the Office of the Australian Information Commissioner and will work with the commissioner to identify any further action that could be taken."
The data breach is understood to have been linked to the University of Canberra's recently-announced voluntary separation program, in which all staff have been offered payment to resign.
Employees who requested estimations of their pay-outs received their colleagues' private information.
The National Tertiary Education Union has already expressed concerns about a perceived lack of planning with the voluntary separation process, including that there are no targets or caps on how many staff can resign.
Union ACT division secretary Rachael Bahl said the NTEU was "appalled" the University of Canberra had accidentally distributed staff information.
"This is the same management who assured staff at the voluntary separation information sessions last week that this process would be entirely confidential," she said.
"This does not instil confidence in the ability of UC to oversee this process in a professional and competent manner."
The University of Canberra did not respond to a question on whether employees' information had made its way outside the institution.