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MonitoringMontana AG filing · May 5, 2026

MemberSource Credit Union Data Breach: What Montana Members Need to Know

MemberSource Credit Union reported a data breach in May 2026 that may have exposed sensitive financial and personal information belonging to its members. If you received a notification letter, your details like Social Security Number and financial account data could be at risk, and you may be eligible to pursue compensation.

This breach is real, not a scam. MemberSource Credit Union officially reported it to the Montana Attorney General on May 5, 2026.

Reviewed by David S. Harris, Esq., data breach and class action attorney (Florida Bar No. 0112739). Free consultation: 786-306-7278

Received a MemberSource Credit Union notification letter? Find out in minutes if you qualify for compensation.

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State
Montana
Breach date
June 3, 2025
Reported
May 5, 2026

What may have been exposed

  • Full Name
  • Social Security Number
  • Financial Account Number
  • Date of Birth
  • Routing Number
  • Credit Score Information
  • Transaction History
  • Mailing Address

MemberSource Credit Union, which serves members in Montana, officially reported a data breach to authorities in May 2026. This incident, which reportedly occurred on June 3, 2025, involved unauthorized access to the credit union's network infrastructure, potentially compromising highly sensitive member data.

The exposed information categories include Full Name, Social Security Number, Financial Account Number, Date of Birth, Routing Number, Credit Score Information, Transaction History, and Mailing Address. The compromise of these data types creates significant risks, such as identity theft, fraudulent financial transactions, and other forms of monetary harm for affected individuals.

Financial institutions are entrusted with safeguarding members' private information and are legally bound to maintain robust security protocols. A data breach suggests these protections may have failed, potentially due to negligence. If you received an official data breach notification letter from MemberSource Credit Union, this document is crucial supporting evidence for pursuing a claim to recover potential damages.

Receiving a data breach notification means you may have legal standing to join others in a class action lawsuit aimed at holding the credit union accountable. Our firm offers a free, no-obligation case review to help you understand your options. You pay nothing upfront, and we only collect a fee if we successfully secure financial recovery on your behalf.

Received the MemberSource Credit Union notification letter? The MemberSource Credit Union case file tracks this filing.

What to do if you were affected

Based on the categories of information reported in this filing, these steps can help limit the risk of identity theft and fraud.

  • Freeze your credit

    Place a free credit freeze with Equifax, Experian, and TransUnion. A freeze blocks new accounts from being opened in your name and can be lifted anytime.

  • Watch your financial accounts

    Review bank and card statements for unfamiliar activity and turn on transaction alerts. Report anything you don't recognize to your bank right away.

  • Stay alert to targeted scams

    Be cautious of calls, texts, or emails that reference this breach. Legitimate organizations won't ask you to confirm sensitive details through an unsolicited message.

  • Keep your notification letter

    Save the notice you received. It documents that your information was involved and is often needed to enroll in any credit monitoring offered or to join a related legal claim.

MemberSource Credit Union data breach settlement, compensation and claim questions

How much could a MemberSource Credit Union data breach settlement or claim be worth?
There is no set amount, and no MemberSource Credit Union settlement is confirmed here. In past data breach settlements, payments depended on what data was exposed and on documented losses — fraud, out-of-pocket costs and time spent dealing with the breach. The filing lists Full Name, Social Security Number, Financial Account Number as involved. Keep receipts and records; they're what damages claims are built on.
Is there a MemberSource Credit Union data breach class action lawsuit?
Law firms often open an investigation after a breach notice like this one, and a class action lawsuit may follow. This page doesn't confirm that a lawsuit has been filed against MemberSource Credit Union. You usually don't have to join a class action to be included — if a settlement is reached, class members are notified and can file a claim.
How many people were affected by the MemberSource Credit Union data breach, and what was exposed?
The filing does not give a count of affected people and lists the following information as involved: Full Name, Social Security Number, Financial Account Number, Date of Birth, Routing Number, Credit Score Information, Transaction History, Mailing Address. Your own letter is the best guide to what was exposed about you, since notices are usually tailored to each person.
Can I sue MemberSource Credit Union over the data breach?
It depends on what was exposed, the law in Montana and your own state, and whether you've been harmed. Most people take part through a class action rather than suing alone. Keep your notification letter — it's the proof that connects you to the breach.
Did MemberSource Credit Union offer free credit monitoring?
Any free monitoring MemberSource Credit Union is offering will be described in the notice you received, along with an activation code and a sign-up deadline. Because Social Security numbers are listed in this filing, identity monitoring and a credit freeze matter more than usual. Enrolling does not give up your right to bring a claim.
Is the MemberSource Credit Union data breach letter legit or a scam?
A notice from MemberSource Credit Union in the mail matches the breach MemberSource Credit Union reported to the Montana Attorney General on May 5, 2026. Check that the company name and dates in your letter match that filing. A real notice of data security incident won't ask for your password, Social Security number or a payment — if it does, contact MemberSource Credit Union through a phone number or website you find yourself.
Do I need a MemberSource Credit Union data breach lawyer or attorney?
A data breach lawyer can tell you whether your situation supports a claim and what it may be worth. A review here is free, and law firms usually take these cases on contingency, so there is no upfront cost.
Where can I see the official MemberSource Credit Union breach notice?
MemberSource Credit Union's report is published by the Montana Attorney General: https://dojmt.gov/office-of-consumer-protection/reported-data-breaches/#mt-membersource-credit-union-2026 Compare it with the letter you received to confirm the dates and details match.
What should I do after getting the MemberSource Credit Union data breach notice?
Keep the letter and the envelope, and note the date it arrived. Freeze your credit with Equifax, Experian and TransUnion, change any passwords the notice mentions, and sign up for any free credit monitoring the letter offers. Then check whether you may have a claim.

Source: Montana Attorney General filing

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