{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-46540","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-05-14T20:42:31.368Z","datePublished":"2026-06-09T23:45:01.847Z","dateUpdated":"2026-06-10T13:00:12.382Z"},"containers":{"cna":{"title":"Nimiq light-blockchain: Light blockchain rebranch issue","problemTypes":[{"descriptions":[{"cweId":"CWE-841","lang":"en","description":"CWE-841: Improper Enforcement of Behavioral Workflow","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L","version":"3.1"}}],"references":[{"name":"https://github.com/nimiq/core-rs-albatross/security/advisories/GHSA-m3pg-qc2q-mg8c","tags":["x_refsource_CONFIRM"],"url":"https://github.com/nimiq/core-rs-albatross/security/advisories/GHSA-m3pg-qc2q-mg8c"},{"name":"https://github.com/nimiq/core-rs-albatross/pull/3706","tags":["x_refsource_MISC"],"url":"https://github.com/nimiq/core-rs-albatross/pull/3706"},{"name":"https://github.com/nimiq/core-rs-albatross/releases/tag/v1.4.0","tags":["x_refsource_MISC"],"url":"https://github.com/nimiq/core-rs-albatross/releases/tag/v1.4.0"}],"affected":[{"vendor":"nimiq","product":"core-rs-albatross","versions":[{"version":"< 1.4.0","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-06-09T23:45:01.847Z"},"descriptions":[{"lang":"en","value":"Nimiq is a Rust implementation of the Nimiq Proof-of-Stake protocol based on the Albatross consensus algorithm. Prior to version 1.4.0, when LightBlockchain::rebranch() adopts a fork chain whose tip is a macro block (checkpoint or election), it only updates self.head but fails to update self.macro_head, self.election_head, self.current_validators, or store the election header in the chain_store. This is in direct contrast with the full Blockchain::rebranch() at blockchain/src/blockchain/push.rs:504-518, which correctly updates all macro/election state when the new head is a macro block. After a rebranch to a macro block, the stale macro_head causes subsequent macro blocks pushed via push() to be verified against the wrong predecessor via verify_macro_successor(&this.macro_head). If the rebranch target was an election block, the stale current_validators causes every subsequent block to fail verify_validators(), completely stalling the light client's chain progression. This issue has been patched in version 1.4.0."}],"source":{"advisory":"GHSA-m3pg-qc2q-mg8c","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-10T12:59:40.645536Z","id":"CVE-2026-46540","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-06-10T13:00:12.382Z"}}]}}