CVE-2026-46403 Klever-Go KVM read-only execution can commit contract delete and upgrade side effects
Attackers can trigger contract deletion and upgrades via read-only execution paths, bypassing intended state isolation in the Klever-Go blockchain library.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-46403?
CVE-2026-46403 is a medium-severity missing authorization vulnerability in klever-io klever-go, published on 21 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Klever-Go is the Go implementation of the Klever blockchain protocol. Prior to 1.7.17, KVM exposes `ExecuteReadOnlyWithTypedArguments` as a read-only execution mechanism. The hook saves the previous read-only state, sets `runtime.SetReadOnly(true)`, executes the destination context, and then restores the previous read-only state. However, the indirect contract delete and upgrade paths do not reject execution when `runtime.ReadOnly()` is true. As a result, a contract reached through read-only execution can call the production delete hook for a target contract it owns. The delete path appends the target address to `vmOutput.DeletedAccounts`, the output context merges `DeletedAccounts` into the caller output, and the smart contract processor later processes the VM output by deleting accounts listed in that field. The root cause is that read-only mode is applied as runtime state, but not enforced by the state-changing delete and upgrade host-core paths. This breaks the expected isolation boundary for workflows that rely on read-only calls to inspect another contract without allowing that callee to produce state-changing VM output. The issue is fixed in v1.7.17. Contract delete and upgrade host-core paths now reject execution when `runtime.ReadOnly()` is true. The invariant is regression-tested for delete, upgrade, storage writes, value transfers, and any VM output field that can later mutate chain state.
Weakness: CWE-693
Which versions are affected by CVE-2026-46403?
3 open source packages ship an affected version, including github.com/klever-io/klever-go.
| Package | Affected | Fixed in |
|---|---|---|
github.com/klever-io/klever-go Go | All versions | 1.7.17 |
github.com/klever-io/klever-go Go | All versions | 1.7.17 |
github.com/klever-io/klever-go Go | All versions | 1.7.17 |
How do I fix CVE-2026-46403?
Upgrade github.com/klever-io/klever-go to 1.7.17 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-46403 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-46403 exists.
Sources
Also known as GHSA-jc6w-wmfc-fh33, GO-2026-5461.