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pypy3 — security advisory

Type: advisorySources: OSVAdvisory ID: DEBIAN-CVE-2021-3426

There's a flaw in Python 3's pydoc. A local or adjacent attacker who discovers or is able to convince another local or adjacent user to start a pydoc server could access the server and use it to disclose sensitive information belonging to the other user that they would not normally be able to access. The highest risk of this flaw is to data confidentiality. This flaw affects Python versions before 3.8.9, Python versions before 3.9.3 and Python versions before 3.10.0a7.

Products
pypy3
Affected versions
Not specified
Fixed versions
7.3.3+dfsg-4
CVEs
CVE-2021-3426
Confirmed fixed CVEs
Not specified
Updated in this feed
30 Oct 2026, 16:46 UTC · Revision 1

Source evidence

DEBIAN-CVE-2021-3426

core-osv · Original source

Published 20 May 2021, 13:15 UTC

There's a flaw in Python 3's pydoc. A local or adjacent attacker who discovers or is able to convince another local or adjacent user to start a pydoc server could access the server and use it to disclose sensitive information belonging to the other user that they would not normally be able to access. The highest risk of this flaw is to data confidentiality. This flaw affects Python versions before 3.8.9, Python versions before 3.9.3 and Python versions before 3.10.0a7.

osv:DEBIAN-CVE-2021-3426

pypy3

Fixed versions: 7.3.3+dfsg-4

pypy3

Fixed versions: 7.3.3+dfsg-4

pypy3

Fixed versions: 7.3.3+dfsg-4

Complete source record
{
  "id": "1b7c0c05663dc0056bde94e370dcf6fb500868ee09e7a10631fdd2f5a9c0d13b",
  "url": "https://osv.dev/vulnerability/DEBIAN-CVE-2021-3426",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "DEBIAN-CVE-2021-3426",
    "summary": "There's a flaw in Python 3's pydoc. A local or adjacent attacker who discovers or is able to convince another local or adjacent user to start a pydoc server could access the server and use it to disclose sensitive information belonging to the other user that they would not normally be able to access. The highest risk of this flaw is to data confidentiality. This flaw affects Python versions before 3.8.9, Python versions before 3.9.3 and Python versions before 3.10.0a7.",
    "evidence": "osv:DEBIAN-CVE-2021-3426",
    "products": [
      {
        "name": {
          "value": "pypy3",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "7.3.3+dfsg-4",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "pypy3",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "7.3.3+dfsg-4",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "pypy3",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "7.3.3+dfsg-4",
            "evidence": "/affected/2/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "DEBIAN-CVE-2021-3426",
      "aliases": [
        "DEBIAN-CVE-2021-3426"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "7.3.3+dfsg-4"
                }
              ]
            }
          ],
          "package": {
            "name": "pypy3",
            "purl": "pkg:deb/debian/pypy3?arch=source&distro=bookworm",
            "ecosystem": "Debian:12"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-3426.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "7.3.3+dfsg-4"
                }
              ]
            }
          ],
          "package": {
            "name": "pypy3",
            "purl": "pkg:deb/debian/pypy3?arch=source&distro=trixie",
            "ecosystem": "Debian:13"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-3426.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "7.3.3+dfsg-4"
                }
              ]
            }
          ],
          "package": {
            "name": "pypy3",
            "purl": "pkg:deb/debian/pypy3?arch=source&distro=forky",
            "ecosystem": "Debian:14"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-3426.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        }
      ],
      "modified": "2026-10-15T09:47:39.558479120Z",
      "provider": "osv",
      "upstream": [
        "CVE-2021-3426"
      ],
      "references": [
        "https://security-tracker.debian.org/tracker/CVE-2021-3426"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2021-3426",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 328178,
  "published_at": "2021-05-20T13:15:07.753+00:00"
}