STARKNET TEMPORARILY HITS BY MAINNET OUTAGE DUE TO EXECUTION LAYER DISCREPANCY

Starknet experienced a temporary mainnet outage on January 11, 2026, due to a state inconsistency between the blockifier execution layer and the proving layer. The proving layer detected the error and rolled back approximately 18 minutes of activity, preventing faulty transactions from reaching Ethereum finality.

This is the second major disruption for Starknet in 2025, following a September outage caused by a sequencer vulnerability.

Starknet, an Ethereum layer-2 (L2) scaling network, faced a brief mainnet outage on January 11, 2026, caused by a discrepancy in state handling between the blockifier execution layer and the proving layer. The incident forced a block reorganization, reverting 18 minutes of network activity and requiring users to resubmit affected transactions.

The outage stemmed from the blockifier incorrectly recording a state write that should have been discarded after a function reverted. This occurred under specific combinations of cross-function calls, variable writes, and reverts, leading to an incorrect execution that the proving layer identified and halted before final settlement on Ethereum.

Starknet has committed to implementing new fuzz-testing suites to compare blockifier execution results with the proving system, helping identify edge-case issues earlier. The team also aims to shorten the time between transaction execution and prover-compatible execution to detect mismatches sooner. These steps aim to enhance the network's stability as it transitions toward a more decentralized architecture.

What Caused the Outage?

The root cause was a mismatch between the execution and proving layers, which led to incorrect transaction execution. Specifically, the blockifier remembered a state-writing that occurred within a reverted function, which should have been discarded. The proving layer detected this inconsistency, preventing the faulty transaction from finalizing on Ethereum.

This incident highlights the complexity of maintaining blockchain networks with multi-layered technology stacks. The mismatch occurred under a specific combination of cross-function calls, variable writes, and reverts, demonstrating how even minor bugs can lead to significant disruptions.

Impact and Response

The 18-minute rollback required users to resubmit affected transactions, which could be problematic for time-sensitive operations. However, the network's total value locked (TVL) remained stable at $840 million, and average transaction fees stayed below one cent.

Starknet resumed normal operations after a block reorganization, and the team has pledged to increase testing and code audits to prevent similar issues. The incident also underscores the need for improved stability as layer-2 technology continues to mature. The proving layer functioned as intended, but ongoing architectural changes and expanded monitoring are necessary to reduce the frequency of such disruptions.

What Does This Mean for Investors?

The incident highlights the risks associated with relying on complex, multi-layered blockchain systems. While the proving layer acted as a safeguard, preventing permanent damage, the network's reliability remains a concern for investors and users.

The STRK token's price rose 1.3% following the outage but remains below its 2024 peak of $4, reflecting ongoing concerns about network reliability and supply dynamics. Investors may need to monitor the network's progress in improving infrastructure coordination and testing protocols to ensure long-term stability.

How Will Starknet Prevent Future Issues?

To mitigate future disruptions, Starknet is implementing new fuzz-testing suites to compare blockifier execution results with the proving system. These tests will help identify edge-case interactions that could lead to incorrect state handling.

Additionally, the team plans to shorten the time between transaction execution and prover-compatible execution, allowing mismatches to be detected sooner. This approach aims to limit how much network activity would need to be rolled back in the future.

The team has also acknowledged the need for improved stability as layer-2 technology continues to evolve. This follows a pattern of interruptions during Starknet's transition to a more decentralized architecture, including the September 2025 outage caused by a sequencer vulnerability.

Starknet's response to this incident demonstrates its commitment to transparency and continuous improvement. The team has emphasized the importance of robust infrastructure to ensure transaction integrity and continuity, particularly in an environment where speed and reliability are critical.

By addressing these issues proactively, Starknet aims to build a more resilient network capable of supporting a wider range of decentralized applications and financial services. This incident serves as a reminder of the challenges involved in maintaining high-throughput, secure, and reliable blockchain systems.