The incident relates to a flaw in a piece of software called MOVEit Transfer
Aer Lingus has confirmed that around 5,000 of its employees have been affected by a cyber attack that has compromised personal information.
The airline is among a number of global companies which has notified staff about the cyber attack. Aer Lingus also says that a "significant but lesser number of former employees" have also been affected.
The incident relates to a flaw in a piece of software called MOVEit Transfer, used by thousands of companies globally to transfer files, which could be exploited by cyber criminals.
Companies using the software were urged last week to take immediate action.
The UK's leading payroll provider Zellis said that eight of its customers have been impacted by the "global issue", which may have exposed personal information, including names, addresses, and banking details.

Unpaid Eight-Month Work And Training Placement For Adults With Disabilities Branded "Extremely Unfair"
Department Of Education Defends Kildare SNA Cuts Amid Claims Of Reduced Need At Some Schools
Naas Nurses Threaten Escalation As Staffing Row Deepens
Driving Tests Face Disruption As RSA Testers To Strike Next Week
Jury Delivers Not Guilty By Reason Of Insanity Verdict In Ballyfin Demesne Strangling Case
Gardaí Arrest Third Suspect As Part Of Investigation Into Multi-County Crime Spree, Including In Kildare
Entire Country Under Status Yellow Ice Warning From Tomorrow
Government To Review HAP After Report Finds No Homes Available Within Limits