{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "core-rs-albatross",
          "vendor": "nimiq",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.4.0"
            }
          ]
        }
      ],
      "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(\u0026this.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\u0027s chain progression. This issue has been patched in version 1.4.0."
        }
      ],
      "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"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-841",
              "description": "CWE-841: Improper Enforcement of Behavioral Workflow",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-09T23:45:01.847Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "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"
        }
      ],
      "source": {
        "advisory": "GHSA-m3pg-qc2q-mg8c",
        "discovery": "UNKNOWN"
      },
      "title": "Nimiq light-blockchain: Light blockchain rebranch issue"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-46540",
    "datePublished": "2026-06-09T23:45:01.847Z",
    "dateReserved": "2026-05-14T20:42:31.368Z",
    "dateUpdated": "2026-06-09T23:45:01.847Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-46540\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-06-10T00:16:54.230\",\"lastModified\":\"2026-06-10T00:16:54.230\",\"vulnStatus\":\"Received\",\"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(\u0026this.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\u0027s chain progression. This issue has been patched in version 1.4.0.\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L\",\"baseScore\":6.5,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"LOW\",\"availabilityImpact\":\"LOW\"},\"exploitabilityScore\":3.9,\"impactScore\":2.5}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-841\"}]}],\"references\":[{\"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\",\"source\":\"security-advisories@github.com\"}]}}"
  }
}