Zebra: Cached Mempool Verification Bypasses Consensus Rules for Ahead-of-Tip Blocks_CVE-2026-40880

{
    "lastseen": "",
    "description": "ZEBRA is a Zcash node written entirely in Rust. Prior to zebrad version 4.3.1 and zebra-consensus version 5.0.2, a logic error in Zebra's transaction verification cache could allow a malicious miner to induce a consensus split. By carefully submitting a transaction that is valid for height H+1 but invalid for H+2 and then mining that transaction in a block at height H+2, a miner could cause vulnerable Zebra nodes to accept an invalid block, leading to a consensus split from the rest of the Zcash network. This vulnerability is fixed in zebrad version 4.3.1 and zebra-consensus version 5.0.2.",
    "published": "2026-04-21T19:18:22.657Z",
    "modified": "2026-04-21T19:52:58.880Z",
    "type": "cve",
    "title": "Zebra: Cached Mempool Verification Bypasses Consensus Rules for Ahead-of-Tip Blocks",
    "source": "GitHub_M",
    "references": "https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-xvj8-ph7x-65gf",
    "id": "CVE-2026-40880",
    "bulletinFamily": "",
    "cwe": [
        "CWE-1025"
    ],
    "cvelist": null,
    "sourceData": "ZcashFoundation zebrad < 4.3.1\nZcashFoundation zebra-consensus < 5.0.2",
    "sourceHref": "",
    "cvss": {
        "score": 7.2,
        "severity": "HIGH",
        "vector": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H",
        "version": "4.0"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "zebrad",
    "version": "< 4.3.1",
    "vendor": "ZcashFoundation",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}