{
  "affected": [
    {
      "database_specific": {
        "unresolved_ranges": [
          {
            "events": [
              {
                "introduced": "0"
              },
              {
                "last_affected": "10.5.6"
              }
            ]
          },
          {
            "events": [
              {
                "introduced": "0"
              },
              {
                "last_affected": "11.0-alpha2"
              }
            ]
          },
          {
            "events": [
              {
                "introduced": "0"
              },
              {
                "last_affected": "11.0-alpha4"
              }
            ]
          },
          {
            "events": [
              {
                "introduced": "0"
              },
              {
                "last_affected": "10.5.6"
              }
            ]
          },
          {
            "events": [
              {
                "introduced": "11.x"
              },
              {
                "last_affected": "11.0a4"
              }
            ]
          }
        ]
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "80c404c4b79f3bcba3fc4585d4c62a62a04f3ed9"
            }
          ],
          "repo": "https://gitlab.torproject.org/tpo/core/tor",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "80c404c4b79f3bcba3fc4585d4c62a62a04f3ed9"
            }
          ],
          "repo": "https://gitlab.torproject.org/tpo/core/tor",
          "type": "GIT"
        }
      ]
    }
  ],
  "details": "Tor Browser through 10.5.6 and 11.x through 11.0a4 allows a correlation attack that can compromise the privacy of visits to v2 onion addresses. Exact timestamps of these onion-service visits are logged locally, and an attacker might be able to compare them to timestamp data collected by the destination server (or collected by a rogue site within the Tor network).",
  "id": "CVE-2021-39246",
  "modified": "2026-03-15T21:49:58.223310713Z",
  "published": "2021-09-24T19:15:07.147Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://gitlab.torproject.org/tpo/core/tor/-/merge_requests/434"
    },
    {
      "type": "ADVISORY",
      "url": "https://www.privacyaffairs.com/cve-2021-39246-tor-vulnerability"
    },
    {
      "type": "FIX",
      "url": "https://gitlab.torproject.org/tpo/core/tor/-/commit/80c404c4b79f3bcba3fc4585d4c62a62a04f3ed9"
    },
    {
      "type": "EVIDENCE",
      "url": "https://github.com/sickcodes/security/blob/master/advisories/SICK-2021-111.md"
    },
    {
      "type": "EVIDENCE",
      "url": "https://sick.codes/sick-2021-111"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ]
}