CVE-2026-46540

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{"affected": [{"affectedData": [{"product": "core-rs-albatross", "vendor": "nimiq", "versions": [{"status": "affected", "version": "< 1.4.0"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "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."}, {"lang": "es", "value": "Nimiq es una implementaci\u00f3n en Rust del protocolo Nimiq Proof-of-Stake basado en el algoritmo de consenso Albatross. Antes de la versi\u00f3n 1.4.0, cuando LightBlockchain::rebranch() adopta una cadena bifurcada cuya punta es un macrobloque (punto de control o elecci\u00f3n), solo actualiza self.head pero no actualiza self.macro_head, self.election_head, self.current_validators, ni almacena el encabezado de la elecci\u00f3n en el chain_store. Esto contrasta directamente con el Blockchain::rebranch() completo en blockchain/src/blockchain/push.rs:504-518, que actualiza correctamente todo el estado de macro/elecci\u00f3n cuando el nuevo head es un macrobloque. Despu\u00e9s de un rebranch a un macrobloque, el macro_head obsoleto causa que los macrobloques subsiguientes empujados a trav\u00e9s de push() sean verificados contra el predecesor incorrecto a trav\u00e9s de verify_macro_successor(&this.macro_head). Si el objetivo del rebranch era un bloque de elecci\u00f3n, los current_validators obsoletos causan que cada bloque subsiguiente falle verify_validators(), deteniendo completamente la progresi\u00f3n de la cadena del cliente ligero. Este problema ha sido parcheado en la versi\u00f3n 1.4.0."}], "id": "CVE-2026-46540", "lastModified": "2026-07-23T09:10:00.113", "metrics": {"cvssMetricV31": [{"cvssData": {"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"}, "exploitabilityScore": 3.9, "impactScore": 2.5, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-46540", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-06-10T12:59:40.645536Z", "version": "2.0.3"}}]}, "published": "2026-06-10T00:16:54.230", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/nimiq/core-rs-albatross/pull/3706"}, {"source": "security-advisories@github.com", "url": "https://github.com/nimiq/core-rs-albatross/releases/tag/v1.4.0"}, {"source": "security-advisories@github.com", "url": "https://github.com/nimiq/core-rs-albatross/security/advisories/GHSA-m3pg-qc2q-mg8c"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-841"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

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