{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "1.1.1"
              },
              {
                "fixed": "1.1.1zj"
              }
            ],
            "source": "AFFECTED_FIELD"
          },
          "events": [
            {
              "introduced": "e04bd3433fd84e1861bf258ea37928d9845e6a86"
            },
            {
              "fixed": "e04bd3433fd84e1861bf258ea37928d9845e6a86"
            }
          ],
          "repo": "https://github.com/openssl/openssl",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "openssl",
    "cwe_ids": [
      "CWE-208"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/77xxx/CVE-2026-77696.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "introduced": "4.0.0"
          },
          {
            "fixed": "4.0.3"
          },
          {
            "introduced": "3.6.0"
          },
          {
            "fixed": "3.6.5"
          },
          {
            "introduced": "3.5.0"
          },
          {
            "fixed": "3.5.9"
          },
          {
            "introduced": "3.4.0"
          },
          {
            "fixed": "3.4.8"
          },
          {
            "introduced": "3.0.0"
          },
          {
            "fixed": "3.0.23"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "Issue summary: SM2 signature generation uses non-constant-time arithmetic\non secret values, forming a timing side-channel.\n\nImpact summary: An attacker able to measure SM2 signing times may learn\ninformation about the per-signature secret nonce, which over many signatures\ncan, via a lattice / Hidden Number Problem attack, lead to recovery of the\nprivate key.\n\nCWE: CWE-208: Observable Timing Discrepancy\n\nDescription: SM2 signature generation computes the signature value using\nvariable-time BIGNUM operations on the secret nonce and the private key, so\nthe time taken to produce an SM2 signature depends on these secret values,\nforming a timing side-channel.\n\nApplications performing SM2 signature generation are affected on all\nplatforms.\n\nFIPS Impact: no\nSM2 is not a FIPS algorithm.",
  "id": "CVE-2026-77696",
  "modified": "2026-09-30T03:30:53.044757817Z",
  "published": "2026-09-29T15:32:22.520Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/77xxx/CVE-2026-77696.json"
    },
    {
      "type": "FIX",
      "url": "https://github.com/openssl/openssl/commit/1c4aed808a7aea32d2d013049c2e0d9fef164fc9"
    },
    {
      "type": "FIX",
      "url": "https://github.com/openssl/openssl/commit/20b20628d39b2dcc4677194bd68c7c060fa598cb"
    },
    {
      "type": "FIX",
      "url": "https://github.com/openssl/openssl/commit/419f5cb519721dceed393dbc524d79e487c72e64"
    },
    {
      "type": "FIX",
      "url": "https://github.com/openssl/openssl/commit/6b90445a56b99a328ac1feba058abf976504f440"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-77696"
    },
    {
      "type": "ADVISORY",
      "url": "https://openssl-library.org/news/secadv/20260929.txt"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Timing Side-Channel in SM2 Signature Generation"
}