{
  "id": "CVE-2026-77696",
  "url": "https://spydr.io/cve/CVE-2026-77696",
  "published": "2026-09-29T16:17:11.493Z",
  "modified": "2026-09-29T21:27:41.130Z",
  "score": 3.7,
  "severity": "low",
  "cvss_version": "3.1",
  "vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
  "score_source": "CISA ADP",
  "epss": 0.00243,
  "epss_percentile": 0.14113,
  "exploited": false,
  "kev": null,
  "ssvc_exploitation": "none",
  "vendors": [
    "OpenSSL"
  ],
  "products": [
    "OpenSSL"
  ],
  "cwes": [
    "CWE-208"
  ],
  "description": "Issue summary: SM2 signature generation uses non-constant-time arithmetic on secret values, forming a timing side-channel. Impact summary: An attacker able to measure SM2 signing times may learn information about the per-signature secret nonce, which over many signatures can, via a lattice / Hidden Number Problem attack, lead to recovery of the private key. CWE: CWE-208: Observable Timing Discrepancy Description: SM2 signature generation computes the signature value using variable-time BIGNUM operations on the secret nonce and the private key, so the time taken to produce an SM2 signature depends on these secret values, forming a timing side-channel. Applications performing SM2 signature generation are affected on all platforms. FIPS Impact: no SM2 is not a FIPS algorithm.",
  "status": "Awaiting Analysis",
  "score_type": "Secondary",
  "scores": {
    "cvss_v40": null,
    "cvss_v31": 3.7,
    "cvss_v30": null
  },
  "references": [
    {
      "url": "https://github.com/openssl/openssl/commit/1c4aed808a7aea32d2d013049c2e0d9fef164fc9",
      "tags": []
    },
    {
      "url": "https://github.com/openssl/openssl/commit/20b20628d39b2dcc4677194bd68c7c060fa598cb",
      "tags": []
    },
    {
      "url": "https://github.com/openssl/openssl/commit/419f5cb519721dceed393dbc524d79e487c72e64",
      "tags": []
    },
    {
      "url": "https://github.com/openssl/openssl/commit/6b90445a56b99a328ac1feba058abf976504f440",
      "tags": []
    },
    {
      "url": "https://openssl-library.org/news/secadv/20260929.txt",
      "tags": []
    }
  ],
  "nvd_url": "https://nvd.nist.gov/vuln/detail/CVE-2026-77696",
  "covered_in": [],
  "attribution": [
    {
      "source": "NVD",
      "url": "https://nvd.nist.gov",
      "notice": "This product uses data from the NVD API but is not endorsed or certified by the NVD."
    },
    {
      "source": "CISA KEV",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "notice": "Known exploited vulnerabilities from the CISA KEV catalog."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss",
      "notice": "Exploit prediction scores from FIRST EPSS."
    }
  ]
}