CVE-2026-41584: Zebrad Zebra Has Rk Identity Point Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-452v-w3gx-72wg",
  "modified" : "2026-05-12T13:32:57Z",
  "published" : "2026-04-18T01:14:57Z",
  "aliases" : [ "CVE-2026-41584" ],
  "summary" : "Zebra has rk Identity Point Panic in Transaction Verification",
  "details" : "# rk Identity Point Panic in Transaction Verification\n\n## Summary\n\nOrchard transactions contain a `rk` field which is a randomized validating key and also an elliptic curve point. The Zcash specification allows the field to be the identity (a \"zero\" value), however, the `orchard` crate which is used to verify Orchard proofs would panic when fed a `rk` with the identity value. Thus an attacker could send a crafted transaction that would make a Zebra node crash.\n\n## Severity\n\n**Critical** - This is a Denial of Service Vulnerability that could allow an attacker to crash Zebra nodes.\n\n## Affected Versions\n\nAll Zebra versions prior to **version 4.3.1**.\n\n## Description\n\nThe vulnerability exists in the `circuits.rs` file of the `orchard` crate; it attempts to get the coordinates of the `rk` value and calls `unwrap()` on the results, which causes a panic if `rk` is the identity.\n\nZebra parses `rk` as a byte vector; it creates an Orchard \"bundle\" using the `orchard` crate and then calls the same crate to verify it, triggering the panic.\n\nAn attacker could exploit this by:\n1. Creating a transaction with a identity `rk`\n2. Submitting it to a Zebra node, making it crash\n\n## Impact\n\n**Denial of Service**\n\n* **Attack Vector:** Network.\n* **Effect:** Node crash.\n* **Scope:** Any impacted Zebra node.\n\n## Fixed Versions\n\nThis issue is fixed in **Zebra 4.3.1**. \n\nThe fix was agreed with `zcashd` developers (which has the same issue) to not allow the identity `rk` anymore and change the specification as such. Zebra now does this when parsing a transaction. This was deemed easier than fixing the issue in `orchard`, which would make the bug public before the nodes could be patched.\n\n## Mitigation\n\nUsers should upgrade to **Zebra 4.3.1** or later immediately. \n\nThere are no known workarounds for this issue. Immediate upgrade is the only way to ensure the node remains not vulnerable to denial of service.\n\n## Credits\n\nThanks to Alex “Scalar” Sol for finding and reporting the issue.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "zebrad"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "4.3.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "zebra-chain"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "6.0.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-452v-w3gx-72wg"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-41584"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/ZcashFoundation/zebra"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-617" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-18T01:14:57Z",
    "nvd_published_at" : "2026-05-08T15:16:41Z"
  }
}