CVE-2026-46403 is a medium-severity (CVSS 6.3) CWE-693 vulnerability in github.com/klever-io/klever-go. O3 Security confirms whether CVE-2026-46403 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Klever-Go KVM read-only execution can commit contract delete and upgrade side effects
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-46403.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-46403 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 360,781 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/klever-io/klever-goReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/klever-io/klever-go | all versions | 1.7.17 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/klever-io/klever-go. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/klever-io/klever-go to 1.7.17 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-46403 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-46403 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-46403. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-46403 in your dependencies?
O3 detects CVE-2026-46403 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.