{"id":"CVE-2026-58262","state":"PUBLISHED","title":"Klever-Go: PubKeysBitmap padding bits bypass the BLS signature quorum","description":"Klever-Go is the Go implementation of the Klever blockchain protocol. Prior to 1.7.20, header signature verification counts the unused padding bits of the PubKeysBitmap toward the two-thirds validator quorum. These padding bits do not correspond to any validator and are ignored by the actual BLS aggregate-signature check, so a malicious or compromised block producer can set them to reach the required quorum while gathering fewer genuine validator signatures than the protocol demands. As a result, nodes that import or intercept the header accept it as correctly signed without a real two-thirds quorum, weakening consensus safety and undermining finality. This issue is fixed in version 1.7.20.","publishedAt":"2026-08-07T22:00:57.154Z","updatedAt":"2026-08-12T22:15:20.657Z","severity":{"score":7.1,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["klever-io klever-go"],"affected":[{"vendor":"klever-io","product":"klever-go","versions":[{"version":"< 1.7.20","status":"affected"}]}],"references":["https://github.com/klever-io/klever-go/security/advisories/GHSA-f9h7-4mmq-vgcq","https://github.com/klever-io/klever-go/commit/a11cb28e495e608d8034dbe83a91e89d0c68e0f7"],"weaknesses":["CWE-345","CWE-347"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/58xxx/CVE-2026-58262.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-58262","state":"PUBLISHED","datePublished":"2026-08-07T22:00:57.154Z","dateUpdated":"2026-08-12T22:15:20.657Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-29T21:54:30.331Z"},"containers":{"cna":{"title":"Klever-Go: PubKeysBitmap padding bits bypass the BLS signature quorum","descriptions":[{"lang":"en","value":"Klever-Go is the Go implementation of the Klever blockchain protocol. Prior to 1.7.20, header signature verification counts the unused padding bits of the PubKeysBitmap toward the two-thirds validator quorum. These padding bits do not correspond to any validator and are ignored by the actual BLS aggregate-signature check, so a malicious or compromised block producer can set them to reach the required quorum while gathering fewer genuine validator signatures than the protocol demands. As a result, nodes that import or intercept the header accept it as correctly signed without a real two-thirds quorum, weakening consensus safety and undermining finality. This issue is fixed in version 1.7.20."}],"affected":[{"vendor":"klever-io","product":"klever-go","versions":[{"version":"< 1.7.20","status":"affected"}]}],"references":[{"url":"https://github.com/klever-io/klever-go/security/advisories/GHSA-f9h7-4mmq-vgcq","name":"https://github.com/klever-io/klever-go/security/advisories/GHSA-f9h7-4mmq-vgcq","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/klever-io/klever-go/commit/a11cb28e495e608d8034dbe83a91e89d0c68e0f7","name":"https://github.com/klever-io/klever-go/commit/a11cb28e495e608d8034dbe83a91e89d0c68e0f7","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":7.1,"baseSeverity":"HIGH","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-345","lang":"en","description":"CWE-345: Insufficient Verification of Data Authenticity","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-347","lang":"en","description":"CWE-347: Improper Verification of Cryptographic Signature","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-07T22:00:57.154Z"},"source":{"advisory":"GHSA-f9h7-4mmq-vgcq","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-12T22:08:08.809887Z","id":"CVE-2026-58262","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-12T22:15:20.657Z"}}]}}}