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MonitoringMontana AG filing · May 5, 2026

MemberSource Credit Union Data Breach: Your Data Exposed

MemberSource Credit Union reported a data breach in May 2026, confirming that sensitive personal and financial information belonging to its members was exposed. This incident, which occurred in June 2025, could put individuals at risk of identity theft and financial fraud, making it crucial to understand the potential impact.

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, operating in Montana, formally reported a data security incident on May 5, 2026, alerting members to a breach of its digital network infrastructure. This incident, which the credit union states occurred on June 3, 2025, indicates that highly sensitive personal and financial data entrusted to MemberSource Credit Union may have been accessed by unauthorized parties. The credit union is currently monitoring the situation.

The breach at MemberSource Credit Union exposed several critical categories of personal information. This includes your 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 details creates a significant risk for identity theft, financial fraud, and unauthorized account access, potentially leading to substantial financial and personal disruption for affected members.

Financial institutions like MemberSource Credit Union are held to strict regulatory standards, including the Gramm-Leach-Bliley Act and state data protection laws in Montana, which mandate robust security measures to protect member data. The occurrence of a data breach raises serious questions about whether these essential safeguards were adequately maintained. When such an incident occurs, it often points to a potential failure in the credit union's duty to protect your confidential information.

If you have received an official data breach notification letter from MemberSource Credit Union, it serves as confirmation that your private information has been compromised. This notice is a critical step, establishing the basis for you to explore your legal options. Our team offers a free, no-obligation case review to help you understand your rights and determine if you are eligible to pursue a claim without any upfront costs.

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 lawyer, lawsuit and letter questions

Do I need a MemberSource Credit Union data breach lawyer or attorney?
You don't need to pay to find out. Our data breach attorneys review notices like this one for free, and data breach cases are usually handled on contingency — no fee unless money is recovered for you.
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.
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.
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.
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.
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.
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.
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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