{"id":"CVE-2026-49343","state":"PUBLISHED","title":"Klever-Go KVM: Throttler slot leak in trie account-data sync causes epoch bootstrap / state sync DoS","description":"Klever-Go is the Go implementation of the Klever blockchain protocol. In versions prior to 1.7.18, the account-data trie syncers are vulnerable to a resource-exhaustion flaw that leaks bounded throttler slots on error paths. In syncDataTrie() (in both userAccountsSyncer.go and kappAccountsSyncer.go), StartProcessing() reserves a slot from the NumGoRoutinesThrottler, but the corresponding EndProcessing() is only called on the success path and on the duplicate-root early return. As a result, any error from trie.NewTrie(), trie.NewTrieSyncer(), or trieSyncer.StartSyncing() (including the network-dependent timeout path) permanently consumes one slot for the lifetime of the throttler. An attacker who can repeatedly cause trie-node sync failures or timeouts during bootstrap can exhaust the bounded throttler, after which further account-data trie syncs stop making progress and SyncAccounts() returns a timeout. Because epoch bootstrap in syncUserAccountsState() and syncKappAccountsState() aborts on any such error, this causes bootstrap to fail, a core availability issue affecting fresh, restarting, or resyncing nodes and validators. This issue is fixed in version 1.7.18.","publishedAt":"2026-08-07T22:18:18.735Z","updatedAt":"2026-08-13T18:40:16.330Z","severity":{"score":5.9,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["klever-io klever-go"],"affected":[{"vendor":"klever-io","product":"klever-go","versions":[{"version":"< 1.7.18","status":"affected"}]}],"references":["https://github.com/klever-io/klever-go/security/advisories/GHSA-fw38-pc54-jvx9","https://github.com/klever-io/klever-go/releases/tag/v1.7.18"],"weaknesses":["CWE-400","CWE-772"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/49xxx/CVE-2026-49343.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-49343","state":"PUBLISHED","datePublished":"2026-08-07T22:18:18.735Z","dateUpdated":"2026-08-13T18:40:16.330Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-05-29T14:35:45.903Z"},"containers":{"cna":{"title":"Klever-Go KVM: Throttler slot leak in trie account-data sync causes epoch bootstrap / state sync DoS","descriptions":[{"lang":"en","value":"Klever-Go is the Go implementation of the Klever blockchain protocol. In versions prior to 1.7.18, the account-data trie syncers are vulnerable to a resource-exhaustion flaw that leaks bounded throttler slots on error paths. In syncDataTrie() (in both userAccountsSyncer.go and kappAccountsSyncer.go), StartProcessing() reserves a slot from the NumGoRoutinesThrottler, but the corresponding EndProcessing() is only called on the success path and on the duplicate-root early return. As a result, any error from trie.NewTrie(), trie.NewTrieSyncer(), or trieSyncer.StartSyncing() (including the network-dependent timeout path) permanently consumes one slot for the lifetime of the throttler. An attacker who can repeatedly cause trie-node sync failures or timeouts during bootstrap can exhaust the bounded throttler, after which further account-data trie syncs stop making progress and SyncAccounts() returns a timeout. Because epoch bootstrap in syncUserAccountsState() and syncKappAccountsState() aborts on any such error, this causes bootstrap to fail, a core availability issue affecting fresh, restarting, or resyncing nodes and validators. This issue is fixed in version 1.7.18."}],"affected":[{"vendor":"klever-io","product":"klever-go","versions":[{"version":"< 1.7.18","status":"affected"}]}],"references":[{"url":"https://github.com/klever-io/klever-go/security/advisories/GHSA-fw38-pc54-jvx9","name":"https://github.com/klever-io/klever-go/security/advisories/GHSA-fw38-pc54-jvx9","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/klever-io/klever-go/releases/tag/v1.7.18","name":"https://github.com/klever-io/klever-go/releases/tag/v1.7.18","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":5.9,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-400","lang":"en","description":"CWE-400: Uncontrolled Resource Consumption","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-772","lang":"en","description":"CWE-772: Missing Release of Resource after Effective Lifetime","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-07T22:18:18.735Z"},"source":{"advisory":"GHSA-fw38-pc54-jvx9","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/klever-io/klever-go/security/advisories/GHSA-fw38-pc54-jvx9","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-13T18:40:07.764602Z","id":"CVE-2026-49343","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-13T18:40:16.330Z"}}]}}}