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Glossary

Proposal Front-Running

Proposal front-running is a blockchain governance attack where an actor observes a pending governance transaction and submits a copy with a higher gas fee to execute first, often to exploit arbitrage opportunities.
Chainscore © 2026
definition
GOVERNANCE ATTACK

What is Proposal Front-Running?

A manipulation tactic in decentralized governance where an actor exploits the public nature of pending proposals to gain an unfair advantage.

Proposal front-running is a form of governance attack where a malicious actor observes a beneficial, pending governance proposal in a Decentralized Autonomous Organization (DAO) or protocol and executes a transaction to capitalize on the expected outcome before the vote is finalized. This is possible because most blockchain governance systems, such as those on Ethereum, make proposal details public in mempools or on-chain before execution. The attacker's goal is typically financial arbitrage—for example, buying an asset expected to rise in value if the proposal passes—or to secure a strategic position, like accumulating voting power to influence the result.

The mechanism relies on the inherent latency between a proposal's submission and its execution. An attacker uses bots to monitor for specific proposal types, such as treasury grants, parameter changes, or token listings. Upon detection, they submit a transaction with a higher gas fee to ensure it is included in a block before the proposal execution transaction. Common techniques include sandwich attacks on associated assets in decentralized exchanges or抢先购买 governance tokens to vote in their favor. This subverts the intended democratic process by allowing external profit-seeking to distort or precede community-decided actions.

Mitigating proposal front-running requires protocol-level design choices. Solutions include implementing a timelock between a vote's conclusion and execution, giving the community time to react to market manipulations. Private voting mechanisms, like zk-SNARKs, can hide vote direction until the voting period ends. Some protocols use commit-reveal schemes for proposal submission. While these increase complexity, they are essential for protecting the integrity of decentralized governance, ensuring that the outcome of a collective decision benefits the protocol and its stakeholders, not opportunistic third parties.

how-it-works
GOVERNANCE ATTACK

How Proposal Front-Running Works

Proposal front-running is a governance attack where a malicious actor anticipates and exploits the predictable execution of a pending proposal to extract value or disrupt the intended outcome.

Proposal front-running, also known as governance sniping, occurs when an attacker analyzes a publicly visible, pending governance proposal and executes a transaction that capitalizes on the proposal's predictable state changes. This is possible because most decentralized autonomous organizations (DAOs) have a time delay between a proposal's submission, its voting period, and its final execution. During this window, the proposal's code and intended actions are transparent on-chain, allowing sophisticated actors to analyze and anticipate its effects on the protocol's state, such as token prices, liquidity pool compositions, or collateral factors.

The attacker's goal is to position themselves financially to profit from the proposal's execution. Common techniques include sandwich attacks on governance token prices, where the attacker buys tokens before a vote that will increase demand and sells immediately after, or parameter arbitrage, where they take leveraged positions based on expected changes to protocol settings like interest rates or collateral ratios. The attack transaction is typically submitted with a higher gas fee to ensure it is included in a block just before the legitimate proposal execution transaction, hence the term 'front-running'.

This vulnerability stems from the inherent transparency and determinism of blockchain systems. While essential for trustlessness, this transparency creates a time-value asymmetry: the proposal's future effects are known before they are applied. Mitigation strategies focus on reducing this predictability, such as implementing timelocks that hide execution details until a delay elapses, using commit-reveal schemes for votes, or designing governance mechanisms where proposal execution does not create obvious, immediately arbitrageable market conditions.

key-features
PROPOSAL FRONT-RUNNING

Key Characteristics

Proposal front-running is a governance attack where a malicious actor exploits the time delay between a proposal's submission and its execution to gain an unfair advantage.

01

Time-Based Exploit

This attack exploits the inherent time delay in on-chain governance. The attacker monitors the mempool for a beneficial proposal, then submits their own transaction with a higher gas fee to execute first. This creates a race condition where the attacker's action is prioritized, allowing them to profit from the market movement the original proposal would have caused.

02

Common Attack Vectors

Front-running targets specific, time-sensitive governance actions:

  • Parameter Changes: Sniping transactions after a proposal to adjust fees, rewards, or collateral ratios.
  • Treasury Management: Profiting from proposals to buy, sell, or allocate treasury assets.
  • Upgrade Execution: Exploiting the activation of new contract logic or features.
03

Technical Prerequisites

Successful front-running requires specific on-chain conditions:

  • Public Mempool: The attacker must be able to see pending transactions.
  • Sufficient Gas: The attacker's transaction must outbid the original with a higher gas price.
  • Predictable Outcome: The proposal's execution must have a clear, exploitable market impact (e.g., a token price change).
04

Distinction from MEV

While both involve reordering transactions for profit, they differ in scope:

  • MEV (Maximal Extractable Value): A broad category encompassing all value extraction from block production, including arbitrage and liquidations.
  • Proposal Front-Running: A specific subset of MEV that exclusively targets governance actions. It is a form of governance-based MEV.
05

Mitigation Strategies

Protocols use several methods to reduce front-running risk:

  • Timelocks: Enforce a mandatory delay between a proposal's approval and its execution, eliminating the surprise element.
  • Execution Privacy: Use solutions like Flashbots SUAVE or encrypted mempools to hide transaction details until inclusion in a block.
  • Governance Minimization: Designing systems where critical parameters are less frequently changed or are permissioned.
06

Real-World Example

A classic scenario involves a DAO treasury proposal to purchase a large amount of a specific token. An attacker sees this pending proposal, buys the token first (driving the price up), and then profits when the DAO's own purchase executes at the inflated price. The attacker's profit comes directly from the DAO's treasury.

examples
PROPOSAL FRONT-RUNNING

Real-World Examples & Attack Vectors

These examples illustrate how proposal front-running manifests in practice, from high-profile governance attacks to the subtle mechanics that enable them.

02

The "Bribe & Run" Vector

An attacker can front-run the voting process itself by:

  • Bribing voters using platforms like Hidden Hand or Votium to concentrate votes on their proposal.
  • Timing the vote to end during low-activity periods.
  • Submitting the execution transaction with a high gas fee the moment the voting period closes, beating any defensive actions from token holders who voted 'No'.
03

Time-Based Vulnerabilities

Many DAOs have inherent timing gaps that create attack surfaces:

  • Voting Delay: The period between a proposal's submission and the start of voting. Attackers can monitor the mempool for proposals and front-run with a competing or malicious one.
  • Timelock vs. Execution: If a passed proposal does not have a timelock (a mandatory waiting period before execution), it can be executed immediately, leaving no time for a community fork or other defensive measures.
04

Mempool Sniping & MEV

Front-running is fundamentally a form of Maximal Extractable Value (MEV). Searchers and bots constantly monitor the public mempool for pending transactions. When a governance proposal submission is detected, they can:

  • Bundle their own transaction to execute first.
  • Sandwich the proposal with other actions to profit from anticipated token price movements.
  • Use private transaction relays to submit their attack without public warning.
05

Defensive Mechanisms

Protocols mitigate front-running through several key designs:

  • Timelocks: A mandatory delay (e.g., 48 hours) between a proposal passing and its execution.
  • Governance Gauges: Systems like veTokenomics that require long-term token locking for voting power, making hostile takeovers expensive.
  • Multisig Guardians: A trusted committee with the power to veto or pause malicious proposals before execution.
  • Snapshot Voting: Off-chain, gas-free voting to gauge sentiment before an on-chain transaction is ever submitted.
06

Related Concepts

  • MEV (Maximal Extractable Value): The broader category of profit from reordering, inserting, or censoring transactions.
  • Flash Loans: A tool often used to temporarily acquire voting power for an attack.
  • Governance Attacks: The umbrella term for exploits targeting decision-making processes.
  • Forking: A last-resort community defense where users migrate to a new chain version that nullifies the malicious proposal's effects.
security-considerations
PROPOSAL FRONT-RUNNING

Security Considerations & Risks

Proposal front-running is a governance attack where a malicious actor exploits the time delay between a proposal's submission and its execution to gain an unfair advantage, typically for financial profit.

01

The Core Mechanism

This attack exploits the proposal lifecycle. An attacker monitors the mempool for a pending governance transaction, decodes its intent, and submits their own transaction with a higher gas fee to execute first. This is possible because most DAO proposals are public on-chain actions, not private votes.

  • Target Phase: The window between proposal submission and execution.
  • Method: Uses gas price auctions to ensure transaction priority.
  • Prerequisite: Requires the proposal's execution logic to be predictable and its outcome to have a monetizable impact on the market.
02

Common Attack Vectors

Front-running targets specific, high-value governance actions.

  • Parameter Changes: Sniping transactions that adjust fees, rewards, or interest rates on a protocol.
  • Treasury Management: Front-running a large token purchase or sale from the DAO treasury to profit from the resulting price movement.
  • Contract Upgrades: If an upgrade includes a token mint or change to tokenomics, an attacker can position themselves before the change takes effect.
  • Grant Approvals: Anticipating and trading around the announcement of a large grant to a project or individual.
03

Real-World Example: Compound

A classic example occurred with Compound's Proposal 62. This proposal aimed to distribute COMP tokens to users of certain markets. An attacker identified the proposal before execution and:

  1. Borrowed large amounts of the affected assets to become eligible for the COMP distribution.
  2. Front-ran the execution to ensure their borrows were registered on-chain at the precise block.
  3. Profited from the allocated COMP tokens, which exceeded their borrowing costs.

This incident cost the protocol millions in unintended token distributions and highlighted the risks of transparent, on-chain execution.

04

Mitigation Strategies

DAOs employ several techniques to reduce front-running risk.

  • Timelocks: A mandatory delay between a proposal's approval and its execution. This removes the element of surprise, allowing the market to price in the change.
  • Execution Privacy: Using Flashbots or similar MEV-protected relays to submit the execution transaction privately, preventing it from being seen in the public mempool.
  • Schedulevuls: Breaking high-impact proposals into multiple, smaller steps to minimize arbitrage opportunities.
  • Governance Minimization: Designing systems where critical parameters are less frequent targets, such as using algorithmic rate setters instead of governance votes.
05

Related Concept: MEV

Proposal front-running is a specific subset of Maximal Extractable Value (MEV). It falls under governance MEV, where value is extracted from the democratic processes of a DAO rather than from DeFi arbitrage or liquidation opportunities.

  • Shared Infrastructure: Both use bots, mempool monitoring, and high-gas bidding.
  • Different Target: Standard MEV often targets DEX arbitrage or lending liquidations. Governance MEV specifically targets the protocol's own control mechanisms.
  • Broader Impact: While financially damaging, governance MEV can also undermine trust in the DAO's decision-making process itself.
06

Key Distinction: Sniping vs. Front-Running

It's crucial to distinguish between two similar attacks:

  • Proposal Front-Running: Acting before a governance action executes to profit from the action itself (e.g., buying an asset before a treasury buy).
  • Vote Sniping: A related attack where an actor acquires voting power (e.g., tokens) after a proposal is submitted but before the voting period ends to swing the outcome, often at the last minute. While both are governance attacks, front-running targets execution, while sniping targets the vote.
mitigation-strategies
MITIGATION STRATEGIES

Proposal Front-Running

Proposal front-running is a governance attack where a malicious actor exploits the time delay between a proposal's submission and its execution to extract value, typically by manipulating on-chain state or financial markets.

Proposal front-running, also known as governance front-running, occurs when an attacker observes a pending governance proposal—such as a parameter change, treasury allocation, or smart contract upgrade—and executes a transaction to profit from the proposal's anticipated effects before it is officially enacted. This is made possible by the transparent and time-bound nature of blockchain-based governance, where proposals are public during voting and execution phases. The attacker's goal is to capitalize on the information asymmetry, acting on the guaranteed future state change before the broader market can react.

Common attack vectors include financial arbitrage and state manipulation. In DeFi protocols, an attacker might see a proposal to change a liquidity pool's fee structure and immediately deposit a large amount of capital to capture future fee revenue. Alternatively, they could front-run a proposal to list a new asset on a decentralized exchange by accumulating that asset off-chain before the listing, aiming to sell at a premium post-execution. These actions undermine the integrity of the governance process by allowing private profit at the expense of the collective.

Mitigation strategies focus on reducing predictability and information leakage. Time-lock mechanisms are fundamental; they enforce a mandatory delay between a proposal's approval and its execution, giving the community time to react to any malicious preparatory transactions. Execution strategies like the Governor Bravo model separate the proposal and execution steps, requiring a separate transaction to trigger the state change. More advanced solutions involve commit-reveal schemes for proposal details or using encrypted mempools to hide transaction intent until execution, though these can add complexity to the governance process.

MECHANISM & IMPACT

Comparison with Other MEV Forms

How proposal front-running differs from other common forms of Maximal Extractable Value based on their core mechanism, target, and network impact.

FeatureProposal Front-RunningArbitrageLiquidationsSandwich Trading

Primary Target

Governance proposals

Price discrepancies across DEXs

Undercollateralized loans

Retail DEX trades

Execution Layer

Consensus layer (block proposal)

Execution layer (mempool)

Execution layer (mempool)

Execution layer (mempool)

Required Capital

High (stake to propose blocks)

Medium (for arbitrage size)

High (to cover liquidation)

High (to manipulate price)

Value Source

Governance outcome influence

Market inefficiency

Liquidation penalties

Slippage from victim trades

Network Impact

Consensus instability, governance attacks

Price efficiency

Protocol solvency

Increased slippage, worse prices

Prevention Difficulty

High (requires protocol changes)

Medium (via private RPCs, Flashbots)

Low-Medium (via keepers)

Medium (via private RPCs)

Victim Awareness

Often delayed or hidden

Price takers are unaffected

Borrowers (immediate penalty)

Traders (immediate worse price)

Typical Timeframe

Epochs (days/weeks)

Block time (< 12 sec)

Block time (< 12 sec)

Single transaction

PROPOSAL FRONT-RUNNING

Frequently Asked Questions

Proposal front-running is a critical governance attack vector in decentralized autonomous organizations (DAOs). These questions address its mechanics, real-world examples, and defensive strategies.

Proposal front-running is a governance attack where a malicious actor exploits the time delay between a proposal's submission and its execution to insert a malicious transaction that executes first. This is achieved by paying a higher transaction fee (gas price) to ensure their transaction is mined in an earlier block. The attacker's goal is typically to alter the state of the smart contract or protocol in a way that benefits them before the legitimate proposal's intended changes take effect. This attack undermines the integrity of on-chain governance by subverting the community's voting outcome.

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Proposal Front-Running: Definition & Attack Vector | ChainScore Glossary