Blockchain data provider Allium discloses unauthorized access, revokes all API keys
Allium blockchain data platform (App, Explorer, Explorer API, datashares)
Allium, a blockchain data provider whose query tools, APIs and warehouse data feeds are used by companies including Visa and Coinbase, disclosed on Oct 28 2026 that it detected unauthorized access to some of its systems on Oct 25. The Allium App and Explorer were offline for about two and a half days. When Explorer and its API came back on Oct 28, Allium revoked existing API keys, required new passwords and recommended MFA, disabled uploading and reading previously uploaded data, and kept Allium Assistant and the Allium MCP offline. It says affected customers were notified directly and an independent security firm is investigating, but it has not said which systems were reached or whether customer data was exposed.
Why this severity: Confirmed unauthorized access with precautionary revocation of all API keys and passwords; scope and any data exposure not yet disclosed
- Started
- Oct 25, 2026
Affected
Not published yet
Fixed in
No fixed release yet
Timeline4
Allium Explorer and Explorer API come back online. Existing API keys are revoked, users must set a new password (MFA recommended), uploading and accessing previously uploaded data is disabled, and Allium Assistant and the Allium MCP stay unavailable.
CEO and co-founder Ethan Chan discloses that Allium detected unauthorized access to some of its systems on Oct 25, says affected customers were notified directly and an independent cybersecurity firm was engaged; the company has not said which systems were accessed or whether customer data was exposed.
Allium takes the whole Allium App offline as a precaution while it works on restoring services.
Allium's Explorer goes offline; the status page first describes it as maintenance and an Explorer outage.
Advisories1
News & write-ups2
Notes & caveats
Allium plans to publish a summary of its findings after the investigation. Datashare gaps from the affected window were still being backfilled for some chains on Oct 28, and uploaded-data features remain disabled.
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