CVE-2026-52878
HIGHCVE-2026-52878 is a high-severity (CVSS 7.5) NULL Pointer Dereference vulnerability in github.com/klever-io/klever-go. O3 Security confirms whether CVE-2026-52878 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Klever-Go: Unauthenticated nil-pointer DoS in P2P transaction validation can halt the chain
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.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-52878.
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-2026-52878 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 0 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. Versions 1.7.14 through 1.7.17 are vulnerable to a nil-pointer panic triggered by a protobuf Transaction whose embedded RawData sub-message is omitted. This omission causes RawData to decode to nil. Every transaction gossiped on the Klever-Go P2P network is decoded and validated synchronously inside the libp2p pubsub topic-validator callback, where txVersionChecker.CheckTxVersion dereferences tx.RawData.Version with no nil check. Because the libp2p pubsub callback, the underlying go-libp2p-pubsub validation worker, and Klever's own network/p2p layer install no recover(), the panic propagates and crashes the entire node process. The attacker payload is a 3-byte protobuf message; no validator key, stake, funds, or on-chain account is required, and delivery aimed at enough of the BLS validator set can halt block production, resulting in a chain halt. This issue has been fixed in version 1.7.18.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/klever-io/klever-go | ≥ 1.7.14&&< 1.7.18 | 1.7.18 |
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 1.7.18 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-52878 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-2026-52878 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-2026-52878. 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-2026-52878 in your dependencies?
O3 detects CVE-2026-52878 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.