Singapore Airlines says roughly 46,000 of its booking records were accessed without authorization through a data breach at Amadeus, the global travel technology provider that supports some of the carrier's reservations and booking processes.

The illegally accessed data included customers' names, booking reference numbers, travel itineraries and booking classes. For about 620 booking records, the exposure went further, potentially reaching email addresses, phone numbers, travel document details and KrisFlyer membership numbers.

Amadeus says it has implemented containment measures and additional security safeguards since the incident.

This is a supply-chain breach: the incident was confined to Amadeus's platform, and Singapore Airlines stressed that its own IT systems were not breached.

That means a single flaw at one Spanish technology firm rippled across carriers worldwide, including Malaysia Airlines, Cathay Pacific and Japan Airlines.

While Amadeus told SIA that no bank account or credit card information was exposed and no bookings were modified, names, itineraries and reference numbers are exactly the data useful for phishing travelers with convincing, trip-specific scams.

The Business Times also reports Amadeus sees no signs the vulnerability was exploited for ransomware purposes, saying it has fixed the vulnerability and added enhanced monitoring and detection capabilities.

The Malay Mail adds that the unauthorised access did not result in any modification to bookings.

Singapore Airlines joins a growing list of carriers reporting customer data compromised in the same Amadeus breach.

Per The Business Times, that roster includes Malaysia Airlines, Cathay Pacific Airways, Japan Airlines and South Korea's Asiana Airlines, while the Malay Mail reports the affected airlines include Korean Air as well as Cathay Pacific, Japan Airlines and Malaysia Airlines.

Cathay Pacific alone has previously disclosed personal details of 53,000 passengers exposed, per related coverage cited by The Business Times, underscoring how widely one provider's glitch can fan out.

Singapore Airlines says it is directly contacting affected customers with upcoming travel and asking them to change their booking reference numbers as a precaution, and it has informed the relevant authorities.

Amadeus has implemented containment measures and additional security safeguards, and its own investigation continues. SIA apologized to affected customers, saying the protection of customers' personal data is of utmost importance.

Travelers should stay alert to phishing that references real itineraries, since booking data — even without payment details — gives scammers credible hooks.