{"cve":{"cve_id":"CVE-2026-46540","is_kev":false,"kev_date_added":null,"kev_vendor_project":null,"kev_product":null,"kev_vulnerability_name":null,"kev_short_description":null,"kev_required_action":null,"kev_due_date":null,"kev_known_ransomware":null,"kev_notes":null,"kev_cwes":null,"epss_score":0.00259,"epss_percentile":0.17018,"epss_as_of":"2026-06-23","description":"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.","published_at":"2026-06-09T23:45:01.847000Z","last_modified_at":null,"cvss_v3_score":6.5,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L","cvss_v3_severity":"MEDIUM","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":null,"ssvc_automatable":null,"ssvc_technical_impact":null,"cwes":["CWE-841"],"nvd_references":["https://github.com/nimiq/core-rs-albatross/security/advisories/GHSA-m3pg-qc2q-mg8c","https://github.com/nimiq/core-rs-albatross/pull/3706","https://github.com/nimiq/core-rs-albatross/releases/tag/v1.4.0"],"vuln_status":null,"trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-06-24T00:09:39.878444Z","updated_at":"2026-06-28T23:30:38.004927Z"},"effective_severity":"MEDIUM","badges":[],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"PR","name":"Privileges Required","value":"N","value_label":"None"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"U","value_label":"Unchanged"},{"metric":"C","name":"Confidentiality","value":"N","value_label":"None"},{"metric":"I","name":"Integrity","value":"L","value_label":"Low"},{"metric":"A","name":"Availability","value":"L","value_label":"Low"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"nimiq","vendor_name":"nimiq","product_slug":"core-rs-albatross","product_name":"core-rs-albatross","version_start":"< 1.4.0","version_start_inclusive":true,"version_end":"< 1.4.0","version_end_inclusive":true,"cpe23_uri":"cve5:nimiq:core-rs-albatross:< 1.4.0:< 1.4.0"}],"exploit_refs":[],"news":[],"references":[{"url":"https://github.com/nimiq/core-rs-albatross/security/advisories/GHSA-m3pg-qc2q-mg8c","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://github.com/nimiq/core-rs-albatross/pull/3706","source_type":"PATCH","tags":["patch"]},{"url":"https://github.com/nimiq/core-rs-albatross/releases/tag/v1.4.0","source_type":"PATCH","tags":["patch"]}],"timeline":[{"type":"published","at":"2026-06-09T23:45:01.847000Z","label":"CVE published","source":null},{"type":"cvss_changed","at":"2026-06-28T17:54:49.174395Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:54:49.174395Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:54:49.174395Z","label":"CVSS score revised","source":"cvelistv5"}]}