Compiler-induced timing leak in sp_256_get_entry_256_9 on RISC-V

{
  "id": "0e6b65d47db9d2c2c99f98137091a5a0a8f1449fd4a10a0188daf4152323998c",
  "url": "https://osv.dev/vulnerability/CVE-2026-3580",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Compiler-induced timing leak in sp_256_get_entry_256_9 on RISC-V",
    "summary": "In wolfSSL 5.8.4, constant-time masking logic in sp_256_get_entry_256_9 is optimized into conditional branches (bnez) by GCC when targeting RISC-V RV32I with -O3. This transformation breaks the side-channel resistance of ECC scalar multiplication, potentially allowing a local attacker to recover secret keys via timing analysis.",
    "evidence": "osv:CVE-2026-3580",
    "products": [],
    "severity": "low",
    "structured": {
      "id": "CVE-2026-3580",
      "aliases": [
        "CVE-2026-3580"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/wolfssl/wolfssl",
              "type": "GIT",
              "events": [
                {
                  "introduced": "59f4fa568615396fbf381b073b220d1e8d61e4c2"
                },
                {
                  "fixed": "922d04b3568c6428a9fb905ddee3ef5a68db3108"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "5.9.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "cpe": "cpe:2.3:a:wolfssl:wolfssl:5.8.4:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "5.8.4"
                      },
                      {
                        "last_affected": "5.8.4"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "5.8.4",
            "v5.8.4-stable",
            "wolfEntropy2d"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-3580.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:23.642265522Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/3xxx/CVE-2026-3580.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-3580",
        "https://github.com/wolfSSL/wolfssl/pull/9855"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-203"
        ],
        "cna_assigner": "wolfSSL",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/3xxx/CVE-2026-3580.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-3580",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 490076,
  "published_at": "2026-03-19T19:46:58.783+00:00"
}