Arbalest Bridge

Lock-and-mint token bridge secured by a validator threshold.

Tokens locked on Ethereum are minted as wrapped representations on Base and Arbitrum after a threshold of validators signs the transfer message. A rate limiter caps outflows per asset and per window.

Ecosystem: Ethereum, Base, Arbitrum
Category: Bridge
Languages: Solidity
Launched: Nov 2025

67.0BElevated risk

Grade B · Elevated risk

Elevated risk; material weaknesses identified.

+2.9 since Nov 2025 · +1.0 since Jul 2026

Quantix Protocol Research · as of 24 Oct 2026 · About this data

Risk Index

How the score is built

Six weighted components, each scored 0–100 where higher means less risk. Points are the component value multiplied by its weight; the gap is what the component costs against a perfect score.

Component	Weight	Value	Points	Gap
Code Security	30%	64	19.2	−10.8
Operational Security	20%	66	13.2	−6.8
Governance Risk	15%	62	9.3	−5.7
Economic Security	15%	74	11.1	−3.9
Infrastructure Resilience	10%	70	7.0	−3.0
Transparency	10%	72	7.2	−2.8
Quantix Risk Index	100%		67.0	−33.0

Risk Index components: Arbalest Bridge Code 64, Operational 66, Governance 62, Economic 74, Infrastructure 70, Transparency 72
Component	Arbalest Bridge
Code	64
Operational	66
Governance	62
Economic	74
Infrastructure	70
Transparency	72

Grade scale

AAA90–100
AA85–89.9
A80–84.9
BBB75–79.9
BB70–74.9
B65–69.9
CCC60–64.9
CC55–59.9
C50–54.9
D0–49.9

Score history

12 monthly snapshots

Each point is the Risk Index computed from that month’s component values. Markers below the chart show the events that moved a component.

Arbalest Bridge Quantix Risk Index by month
Period	Quantix Risk Index
Nov ’25	64.1
Dec ’25	64.1
Jan ’26	65.0
Feb ’26	65.0
Mar ’26	65.0
Apr ’26	65.0
May ’26	66.0
Jun ’26	66.0
Jul ’26	66.0
Aug ’26	66.0
Sep ’26	66.0
Oct ’26	67.0

6 Oct 2026
Research assessment
Research assessment completed: Bridge Security Assessment
8 findings (1 critical, 2 high, 3 medium, 1 low, 1 informational). 1 critical or high finding remains open.
Read the research assessment
- Code Security+3
- Transparency+1
11 May 2026
Governance
Validator set expanded
Threshold moved from 3-of-5 to 5-of-9 with operators on two providers.
- Governance Risk+5
- Infrastructure Resilience+3
26 Jan 2026
Economic
Rate limiter deployed
Per-asset outflow caps on the gateway.
- Economic Security+6

Risk factors

What keeps the score from being higher, most severe first.

HighCode SecurityFrom the research assessment
1 open critical or high finding
The research assessment reports 0 critical and 1 high findings still open or partially resolved. Code Security reflects this exposure until fixes are verified.
HighGovernance RiskProfile analysis
Validator quorum controls upgrades
The same five keys that approve transfers can replace the gateway logic, so a quorum compromise is total compromise.
MediumEconomic SecurityProfile analysis
Per-asset, not global, rate limits
An attacker with forged approvals could drain several assets in parallel, each under its own cap.
MediumTransparencyProfile analysis
Unverified destination contracts
Users cannot independently confirm the wrapped-token logic on destination chains.

Recommendations

Each recommendation raises one component to a target value. The score effect is recomputed with the Risk Index model, holding every other component fixed.

Governance Risk: 62 → 78
72-hour timelock on upgrades and validator rotation
Separate the upgrade role from the validator set and delay its actions.
+2.4
→ 69.4
Economic Security: 74 → 82
Global outflow cap
Bound total value released per window across all assets.
+1.2
→ 68.2
Transparency: 72 → 82
Verify all destination deployments
Publish and verify wrapped-token implementations and proxies.
+1.0
→ 68.0

Analysis

Contract, governance and operations

Contract analysis

Source: Partially verified
Upgradeability: Transparent proxy
Administrative control: 5-of-9 validator multisig, no upgrade delay
Enforced delay: None identified
External dependencies: Validator signing infrastructure; Destination-chain RPC providers

CautionValidator threshold. 5 of 9 signatures release funds or mint wrapped tokens.
FailUpgrade delay. Gateway and verifier upgrades execute immediately.
PassRate limiter. Per-asset outflow caps per window.
CautionDestination verification. Wrapped token implementations on Base and Arbitrum not yet verified.

Governance exposure

High

The validator multisig controls both message approval and upgrades; there is no delay between a decision and its execution.

Operational resilience

Adequate

Validators run on two cloud providers; key ceremonies are documented but not independently witnessed.

Monitoring

Monitoring history

2 recorded security events for Arbalest Bridge, most recent first.

Open in Security Monitoring

2 Jun 2026InformationalUSDC outflow at 62% of the 6-hour limitWhale Activity · RateLimiterResolved
27 Jan 2026MediumWETH outflow at 86% of the 6-hour limitWhale Activity · RateLimiterResolved

Research assessment

QX-TSA-2026-005Bridge Security AssessmentUnder Review

Lock-and-mint bridge contracts on Ethereum, Base and Arbitrum: gateway, message verification, validator set, token vault, wrapped token and rate limiter.

Review 21 Sept 2026 – 6 Oct 2026

Critical1

High2

Medium3

Low1

Informational1

4 resolved
1 partially resolved
1 acknowledged
2 open

Read the assessment

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Research

Relevant research

Publications on the risks that matter most for a bridge protocol.

Architecture

System components

Gateway: Locks and releases canonical tokens on the source chain
MessageVerifier: Checks validator signatures over transfer messages
ValidatorSet: Validator membership, threshold and rotation
WrappedToken: Mintable representation on destination chains
RateLimiter: Per-asset outflow caps

Turn risk factors into a remediation plan.

A research assessment traces each weakness to code, configuration or process, and verifies the fix before the score moves.

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