Foreword

In April 2026, two cross-chain bridge attacks occurred in succession, shaking the DeFi world once again.

First, on April 18, KelpDAO was hacked and had approximately $293 million stolen due to a cross-chain verification configuration flaw; then, on April 29, the Syndicate Commons cross-chain bridge experienced a nearly 35% token plunge due to missing message verification.

The attackers did not touch the core smart contract code, but instead exploited a "trust blind spot" in the design of cross-chain bridges—by forging a message, the system obediently allowed it to pass.

These two incidents once again expose a core problem:

👉Cross -chain bridges are becoming one of the "biggest weaknesses" in blockchain security.

For ordinary users and project teams, these two incidents serve as a wake-up call: the underlying trust model of cross-chain bridges is being systematically challenged. This article addresses the nature of the risks and provides practical protection recommendations.

Part 01 — Why are cross-chain bridges prone to "overturning"?

Frequent accidents involving cross-chain bridges stem from several common design flaws:

1. The verification mechanism is too simple.

With only a single node needing to confirm, a hacker can forge commands by breaching just one node. This "single point of trust" model is essentially defenseless in a decentralized world.

2. Lack of two-way reconciliation

If something didn't happen on the source chain, the target chain can't identify it, allowing for the unimpeded forwarding of messages. It's like a bank only looking at the check in your hand, but not calling to verify the account balance.

3. Overly centralized permissions

Large-scale funds pools have no limits, delays, or multi-signature protection; a single breach can lead to the entire amount being transferred out. It's like a safe where only one person holds the key; if it's lost, everything is lost.

4. Inadequate auditing

Many vulnerabilities are only discovered months after deployment, leaving a persistent window for attacks. Initial audits do not guarantee continued security; new techniques always emerge after the audits are completed.

Both of these incidents essentially stemmed from "trusting a single link that shouldn't have been trusted."

Part 02 — Common Risk Types of Cross-Chain Bridges

Every link in a cross-link bridge can be a potential vulnerability; please be vigilant when using it.

1. Vulnerability in verification mechanism

Single sign-on is easily compromised; forged messages can pass. Once hackers control the verification node, they essentially have the "give-up button" for all cross-chain assets.

2. Contract logic flaws

Such as missed permission checks, reentrancy vulnerabilities, etc. These small oversights at the code level often become "backdoors" that can be repeatedly exploited.

3. Risks associated with centralized nodes

Once servers, APIs, and keys are compromised, the system spirals out of control. The centralized components upon which cross-chain bridges rely are precisely the most favored entry points for nation-state hackers.

4. Data credibility issues

External data hijacking or tampering can lead to erroneous execution. Contamination of oracles or off-chain data sources can cause the entire bridge to "go in the wrong direction."

5. Centralized fund pooling

Large sums of money without risk control are quickly lost once a breach occurs. Pooling all users' funds into one pool is tantamount to providing hackers with an opportunity to "wipe them all out."

Users don't need to remember all the technical details; they only need to know that problems can occur at any step of a cross-chain bridge.

Part 03 — How can ordinary users protect themselves?

This part is the most crucial—many losses are actually due to operational habits.

✅ Minimize the frequency of cross-chain operations

Every cross-chain transaction involves entrusting assets to a third party for processing; any problem in any step could lead to asset loss.

💡 Recommendation:

• Avoid frequent cross-chain transfers unless absolutely necessary.

• Prioritize established and reliable cross-chain bridges, avoiding niche and less popular tools.

📌 Core Principles:

The more cross-chain transactions, the higher the risk of exposure.

✅ Do not use newly launched cross-chain bridges

Many cross-chain bridges, when they were first launched:

• The code has not been fully tested in real-world scenarios.

• There may be omissions in the audit.

• Risk control mechanisms are not yet perfect

This is precisely the "window of opportunity" that hackers love most.

💡 Recommendation:

• Avoid newly launched or overly hyped projects

• Observe for a period of time to see if any abnormalities or security incidents occur.

👉 Remember this sentence:

Newer does not necessarily mean safer; in many cases, it can actually be riskier.

✅ Test with a small amount before making a larger transaction.

Many users are accustomed to directly transferring large sums of money, which carries extremely high risks. It is recommended that when using an unfamiliar cross-chain bridge for the first time, transfer a small amount to test the entire process and confirm that the funds have arrived correctly before proceeding with larger transactions. This way, even if problems arise, losses can be controlled.

👉 The significance of doing this is:

Even if problems arise, the losses are manageable, rather than a "one-time landmine".

✅ Exercise caution when appropriating and signing documents.

The entire process of cross-chain operations is almost always accompanied by wallet contract authorization, and authorization is the core entry point for the theft of most user assets.

⚠️ Key risk points:

• Unlimited Contract Authorization: Allows unlimited transfer of all corresponding assets in your wallet.

• Blindly authorizing unfamiliar contracts greatly increases the risk of phishing attacks and cryptocurrency theft.

💡 Protective measures:

• Revoke the authorization promptly after completing the operation.

• Do not readily accept unfamiliar signatures; verify the address and permissions before signing.

✅Manage your assets through separate wallets to avoid "total loss in one go".

Many users concentrate all their assets in one wallet, and if a risk occurs (such as authorization abuse or private key leakage), the loss will be all assets.

👉 Safer approach:

• Main wallet: Used only for storing large amounts of assets (does not participate in interactive activities).

• Wallet Operations: Used for everyday operations such as DeFi and cross-chain communication.

• High-risk operation: A new wallet can be used independently.

📌 Protective effect:

Even if your wallet is attacked or robbed during daily operations, your core large assets will not be affected, preventing your assets from being completely wiped out and lost.

Part 04 — Safety Issues That Project Owners Must Pay Attention To

If what users can do is "reduce risk," then what project teams must do is "avoid accidents."

1. Decentralized verification

Multi-node consensus eliminates single points of failure. There must be at least three independent verification nodes, and they cannot share the same infrastructure.

2. Minimize permissions + time lock

Split administrator privileges and force a 24-hour delay for critical operations. This way, even if privileges are stolen, the team and users will still have a window to react.

3. Continuous auditing and monitoring

Pre-launch auditing is just the beginning; 24/7 monitoring of abnormal transactions is necessary after launch. Many attacks occur "after the audit," making dynamic protection more important than a one-time check.

4. Fund segregation

Don't put all your assets in one pool; manage them in layers. Separate the agreement's own funds, user collateral, and platform fees into different pools so that if one pool fails, it won't affect the whole pool.

Conclusion

The KelpDAO and Syndicate Commons incidents once again prove that:

Cross-chain bridges are not "functional components" but "high-risk infrastructure".

From verifying vulnerabilities to losing control of privileges, every step can become an entry point for attacks. The two incidents differ in their methods, but share the same underlying issue: overly simplistic assumptions about trust.

For ordinary users:

👉 Reducing cross-chain transactions, exercising caution in authorization, and diversifying assets are the most effective protection measures.

For the industry:

👉 Decentralized verification, access control, and transparency mechanisms are key directions for cross-chain security.