{"id":"CVE-2026-52878","aliases":["GHSA-rm5c-5x2p-48wr","GO-2026-5628"],"url":"https://o3.security/vulnerability/CVE-2026-52878","summary":"Klever-Go: Unauthenticated nil-pointer DoS in P2P transaction validation can halt the chain","details":"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.","published":"2026-08-07T22:32:27.340Z","modified":"2026-08-12T03:51:28.009728683Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":{"score":0.00278,"percentile":0.20424,"asOf":"2026-08-20"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/klever-io/klever-go","fixedVersion":"1.7.18"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/klever-io/klever-go/releases/tag/v1.7.18"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52878.json"},{"type":"ADVISORY","url":"https://github.com/klever-io/klever-go/security/advisories/GHSA-rm5c-5x2p-48wr"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-52878"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:28.009728683Z"}}