Skip to content
Heist/ feed
Back to feed
High

Zebra before 6.0.0 Denial of Service via Synchronous Script FFI Verification

Type: advisorySources: OSV

Zebra before 6.0.0 contains a denial of service vulnerability that allows unauthenticated peers to stall Tokio workers by submitting mempool transactions requiring expensive synchronous script verification. Attackers can send non-standard high-sigop P2SH transactions that reach CachedFfiTransaction::is_valid() before standardness checks, saturating the verifier buffer and rendering the node unresponsive.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2026-104431
Confirmed fixed CVEs
Not specified
Updated in this feed
5 Nov 2026, 03:43 UTC · Revision 1

Source evidence

Zebra before 6.0.0 Denial of Service via Synchronous Script FFI Verification

core-osv · Original source

Published 2 Oct 2026, 11:38 UTC

Zebra before 6.0.0 contains a denial of service vulnerability that allows unauthenticated peers to stall Tokio workers by submitting mempool transactions requiring expensive synchronous script verification. Attackers can send non-standard high-sigop P2SH transactions that reach CachedFfiTransaction::is_valid() before standardness checks, saturating the verifier buffer and rendering the node unresponsive.

osv:CVE-2026-104431
Complete source record
{
  "id": "d171ea785839a6f1a932414203f0ff9b995e7c9800f3b365f3fdfbfff3ab59c0",
  "url": "https://osv.dev/vulnerability/CVE-2026-104431",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Zebra before 6.0.0 Denial of Service via Synchronous Script FFI Verification",
    "summary": "Zebra before 6.0.0 contains a denial of service vulnerability that allows unauthenticated peers to stall Tokio workers by submitting mempool transactions requiring expensive synchronous script verification. Attackers can send non-standard high-sigop P2SH transactions that reach CachedFfiTransaction::is_valid() before standardness checks, saturating the verifier buffer and rendering the node unresponsive.",
    "evidence": "osv:CVE-2026-104431",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-104431",
      "aliases": [
        "CVE-2026-104431",
        "GHSA-84j3-rw4c-gqmj"
      ],
      "metrics": [
        {
          "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:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/zcashfoundation/zebra",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "bb41d69013edbfa8594bb097fa751f47eeb31445"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "6.0.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "6.0.0"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v6.0.0-rc.0",
            "v5.2.0",
            "v5.1.0",
            "v5.1.1",
            "v5.0.0",
            "v4.5.1",
            "v4.5.0",
            "v4.4.0",
            "v4.4.1",
            "v4.3.1",
            "4.3.1",
            "v4.3.0",
            "v4.2.0",
            "v4.1.0",
            "v4.0.0",
            "v3.1.0",
            "v3.0.0",
            "v3.0.0-rc.0",
            "v2.5.0",
            "v2.0.1",
            "v2.4.2",
            "v2.3.0",
            "v2.4.0",
            "v2.0.0",
            "v2.2.0",
            "v2.1.0",
            "v2.0.0-rc.0",
            "v1.9.0",
            "v1.8.0",
            "v1.7.0",
            "v1.6.1",
            "v1.6.0",
            "v1.5.2",
            "v1.5.1",
            "v1.5.0",
            "v1.4.0",
            "v1.3.0",
            "v1.2.0",
            "v1.1.0",
            "v1.0.1",
            "v1.0.0",
            "v1.0.0-rc.9",
            "v1.0.0-rc.8",
            "v1.0.0-rc.7",
            "v1.0.0-rc.6",
            "v1.0.0-rc.5",
            "v1.0.0-rc.0",
            "v1.0.0-rc.4",
            "v1.0.0-rc.3",
            "v1.0.0-rc.2",
            "v1.0.0-rc.1",
            "v1.0.0-beta.15",
            "v1.0.0-beta.14",
            "v1.0.0-beta.13",
            "v1.0.0-beta.12",
            "v1.0.0-beta.11",
            "v1.0.0-beta.10",
            "v1.0.0-beta.9",
            "v1.0.0-beta.8",
            "v1.0.0-beta.7",
            "v1.0.0-beta.6",
            "v1.0.0-beta.5",
            "v1.0.0-beta.4",
            "v1.0.0-beta.3",
            "v1.0.0-beta.2",
            "v1.0.0-beta.1",
            "v1.0.0-beta.0",
            "v1.0.0-alpha.19",
            "v1.0.0-alpha.18",
            "v1.0.0-alpha.17",
            "v1.0.0-alpha.16",
            "v1.0.0-alpha.15",
            "v1.0.0-alpha.14",
            "v1.0.0-alpha.13",
            "v1.0.0-alpha.12",
            "v1.0.0-alpha.11",
            "v1.0.0-alpha.10",
            "v1.0.0-alpha.9",
            "v1.0.0-alpha.8",
            "v1.0.0-alpha.7",
            "v1.0.0-alpha.6",
            "v1.0.0-alpha.5",
            "v1.0.0-alpha.4",
            "v1.0.0-alpha.3",
            "v1.0.0-alpha.2",
            "v1.0.0-alpha.1",
            "v1.0.0-alpha.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-104431.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:42.444846859Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/104xxx/CVE-2026-104431.json",
        "https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-84j3-rw4c-gqmj",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-104431",
        "https://www.vulncheck.com/advisories/zebra-before-6.0.0-denial-of-service-via-synchronous-script-ffi-verification"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-405"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/104xxx/CVE-2026-104431.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-104431",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 509939,
  "published_at": "2026-10-02T11:38:10.56+00:00"
}