Gnosis Pay Reported Customer Data Breach Following Unauthorized Access to Its Card System

The incident was discovered on November 3, 2026, and containment efforts began within two hours.

According to the company, users’ funds were not affected, but some personal information was exposed.

Gnosis Pay has introduced mandatory 3D Secure for online payments and plans to retire the vulnerable B2C system on December 20.

Gnosis Pay reported a user data leak following unauthorized access to the system that powers its branded payment cards. The incident was discovered on November 3, 2026, and the attackers gained access to certain customer information.

We had a data breach affecting the system powering Gnosis Pay-branded cards (our B2C business line) that resulted in the exposure of certain customer information. Everyone affected was sent an email today with full information. We deeply regret that this happened. While funds were not affected, the security of personal information is just as important and we take full responsibility. Additional measures are in place until the B2C platform involved is fully retired as planned on 20 December 2026. In the meantime we encourage everyone to be even more vigilant. We will never ask for your PIN or seed phrase, or ask you to move funds. Further Details: We encourage security researchers to communicate security vulnerabilities directly with us via [email protected]. The same rewards apply as to Gnosis Chain: — Gnosis Pay 💳 (@gnosispay) November 6, 2026

We had a data breach affecting the system powering Gnosis Pay-branded cards (our B2C business line) that resulted in the exposure of certain customer information. Everyone affected was sent an email today with full information. We deeply regret that this happened. While funds were not affected, the security of personal information is just as important and we take full responsibility. Additional measures are in place until the B2C platform involved is fully retired as planned on 20 December 2026. In the meantime we encourage everyone to be even more vigilant. We will never ask for your PIN or seed phrase, or ask you to move funds. Further Details: We encourage security researchers to communicate security vulnerabilities directly with us via [email protected]. The same rewards apply as to Gnosis Chain:

At the same time, the company said users’ funds were not affected. The leak was limited to Gnosis Pay’s B2C line and did not impact the corporate platform that supports all partner card programs.

The team reported the incident on its blog and said every affected customer was sent an email with details on the specific data that was accessed from their account.

Gnosis Pay Strengthened Security After Data Leak

According to the company, after detecting the unauthorized access, the security team immediately began its response. Containment started within two hours, after which Gnosis Pay replaced compromised security credentials and remediated the vulnerability.

The company also introduced additional security measures that will remain in place until the B2C platform is retired. These include:

Enhanced monitoring of card transactions and wallets to detect fraud and attempts to gain access to funds

Mandatory 3D Secure verification for all online payments

Specialized monitoring for potential misuse of stolen information

Gnosis Pay clarified that the affected system was already scheduled to be decommissioned on December 20, 2026. The corporate platform that supports card programs under partners’ brands was not affected. Partners, the relevant data protection authorities, and the card issuer were also notified the leak.

“We deeply regret that this happened. While funds were not affected, the security of personal information is just as important and we take full responsibility,” the company said.

Customers Warned Potential Phishing Attacks

Gnosis Pay urged users to be especially cautious unexpected emails, messages, calls, and postal mail that allegedly relate to the service, partner apps, or payment cards. Even if such messages contain real personal data or purchase information, the company advises users not to click links and instead open the official Gnosis Pay web app or a partner app on their own.

Separately, the team emphasized that it will never ask users to :

A PIN, seed phrase, or private keys

The full payment card number

Transfer funds or re-verify their identity via email or SMS

According to the company, all account changes take place only in the official app. Gnosis Pay is also conducting a full review of the incident and plans to apply the findings to its other systems.

As a reminder, in October 2026, the L1 blockchain Qubic reported a major security incident: 2.94 trillion QU was stolen from 1,404 wallets. According to the team, the cause was insufficient randomness during the generation of parts of some seed phrases, rather than a vulnerability in the protocol itself.

Previously, other hardware crypto wallet makers also reported leaks of customers’ personal data. In particular, Trezor disclosed information 13,689 customers after its logistics partner ShipMonk was hacked, while emphasizing that the company’s own systems and devices were not affected.

Hardware wallet maker Keystone also confirmed a leak of names, details, shipping addresses, and order history following a hack of its official website, but assured users that private keys, seed phrases, and payment information remained secure.

In addition, SlowMist experts found malicious JavaScript code in Udesk’s support system that could steal user data and replace deposit addresses on certain crypto platforms.