Zilliqa, a high‑throughput blockchain known for its fast and low‑cost transactions, has temporarily stopped all native ZIL transfers after a critical security flaw was uncovered in its Ledger hardware wallet application. The bug, dating back to 2019, allows an attacker to recover the private key of a Ledger‑protected wallet from the public signatures that appear on the blockchain when native ZIL transactions are signed.
The first sign of trouble emerged when an exchange partner’s cold wallet suffered a theft of an undisclosed amount of ZIL on July 19, 2026. The project’s public announcement on July 20 confirmed that the stolen funds were taken from a cold‑storage device, but the precise technical cause was not disclosed at the time. Within hours, Zilliqa’s core team identified a flaw in the native transaction signing pathway of the Ledger app that could compromise keys that had already broadcasted at least five native ZIL transactions.
Because each native transaction signature is recorded on‑chain, the exposure is irreversible; even a future update of the Ledger firmware cannotmandu reverse the compromise. Consequently, the project instructed affected users to abandon the compromised keys immediately rather than rely on an app patch alone. In contrast, EVM‑based transactions and those signed with official SDKs such as zilliqa-js, gozilliqa-sdk, and pyzil remain safe, as the vulnerability is isolated to the legacy native signing path.
To mitigate the risk of the stolen funds being moved or sold through centralized platforms, Zilliqa asked all exchanges to pause deposits and withdrawals of ZIL. The pause was lifted only after the team confirmed that the root cause was technical and not related to wallet managementגב or operational procedures on the exchange side. The incident prompted a swift internal audit that traced the flaw to an oversight in the cryptographic routine that failed to enforce proper key separation during the signing process.
Industry analysts note that the incident underscores the importance of rigorous security reviews for hardware wallet integrations, especially on projects that support multiple transaction types. The fact that the vulnerability had existed for several years highlights a gap in the supply chain testing that could have been addressed with a more frequent firmware audit. Moving forward, Zilliqa has pledged to release an updated Ledger app version that eliminates the key recovery vector and will perform a comprehensive audit of all legacy wallet software.
Users who own ZIL and have used Ledger devices for native transactions should check the number of broadcasted native transactions recorded on their addresses. If the count is five or more, they should transfer their holdings to a new address that has not been exposed to the Ledger signing API. The sallower that these steps are standard best practices for managers of crypto assets, the incident will serve as a cautionary tale for the broader ecosystem about the potential for subtle bugs to compromise key security.
While the halt of native ZIL transfers has temporarily disrupted trading activity, it is a critical step that protects the integrity of the network and the confidence of its users. Zilliqa’s transparent communication and rapid response demonstrate a commitment to security that, if followed by a thorough remediation plan, can restore normal operations without compromising the safety of holders.
