ubuntu-cve-2026-59884
Vulnerability from osv_ubuntu
Published
2026-07-14 17:17
Modified
2026-07-14 17:17
Summary
Details

pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.4, the BER decoder shared by the CER and DER codecs parses long-form tags by accumulating continuation octets without an upper bound on the tag ID size, allowing a crafted input to force construction of an arbitrarily large integer with CPU cost growing quadratically and to trigger unhandled ValueError exceptions in Python 3.11+ error formatting paths. Any application decoding untrusted BER, CER, or DER input is affected. This issue is fixed in version 0.6.4.

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python-pyasn1",
            "binary_version": "0.1.7-1ubuntu2.1+esm1"
          },
          {
            "binary_name": "python3-pyasn1",
            "binary_version": "0.1.7-1ubuntu2.1+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:14.04:LTS",
        "name": "pyasn1",
        "purl": "pkg:deb/ubuntu/pyasn1@0.1.7-1ubuntu2.1+esm1?arch=source\u0026distro=esm-infra-legacy/trusty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.1.4-0ubuntu1",
        "0.1.7-1ubuntu1",
        "0.1.7-1ubuntu2",
        "0.1.7-1ubuntu2.1",
        "0.1.7-1ubuntu2.1+esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "pypy-pyasn1",
            "binary_version": "0.1.9-1ubuntu0.1~esm1"
          },
          {
            "binary_name": "python-pyasn1",
            "binary_version": "0.1.9-1ubuntu0.1~esm1"
          },
          {
            "binary_name": "python3-pyasn1",
            "binary_version": "0.1.9-1ubuntu0.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "pyasn1",
        "purl": "pkg:deb/ubuntu/pyasn1@0.1.9-1ubuntu0.1~esm1?arch=source\u0026distro=esm-infra/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.1.8-2",
        "0.1.9-1",
        "0.1.9-1ubuntu0.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "pypy-pyasn1",
            "binary_version": "0.4.2-3ubuntu0.18.04.1~esm1"
          },
          {
            "binary_name": "python-pyasn1",
            "binary_version": "0.4.2-3ubuntu0.18.04.1~esm1"
          },
          {
            "binary_name": "python3-pyasn1",
            "binary_version": "0.4.2-3ubuntu0.18.04.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "pyasn1",
        "purl": "pkg:deb/ubuntu/pyasn1@0.4.2-3ubuntu0.18.04.1~esm1?arch=source\u0026distro=esm-infra/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.1.9-2",
        "0.4.2-3",
        "0.4.2-3ubuntu0.18.04.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "pypy-pyasn1",
            "binary_version": "0.4.2-3ubuntu0.20.04.1~esm1"
          },
          {
            "binary_name": "python-pyasn1",
            "binary_version": "0.4.2-3ubuntu0.20.04.1~esm1"
          },
          {
            "binary_name": "python3-pyasn1",
            "binary_version": "0.4.2-3ubuntu0.20.04.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "pyasn1",
        "purl": "pkg:deb/ubuntu/pyasn1@0.4.2-3ubuntu0.20.04.1~esm1?arch=source\u0026distro=esm-infra/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.4.2-3",
        "0.4.2-3build1",
        "0.4.2-3ubuntu0.20.04.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "pypy-pyasn1",
            "binary_version": "0.4.8-1ubuntu0.2"
          },
          {
            "binary_name": "python3-pyasn1",
            "binary_version": "0.4.8-1ubuntu0.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "pyasn1",
        "purl": "pkg:deb/ubuntu/pyasn1@0.4.8-1ubuntu0.2?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.4.8-1",
        "0.4.8-1ubuntu0.1",
        "0.4.8-1ubuntu0.2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-pyasn1",
            "binary_version": "0.4.8-4ubuntu0.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "pyasn1",
        "purl": "pkg:deb/ubuntu/pyasn1@0.4.8-4ubuntu0.2?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.4.8-4",
        "0.4.8-4ubuntu0.1",
        "0.4.8-4ubuntu0.2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-pyasn1",
            "binary_version": "0.6.3-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "pyasn1",
        "purl": "pkg:deb/ubuntu/pyasn1@0.6.3-1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.6.1-1",
        "0.6.1-1build1",
        "0.6.2-1",
        "0.6.3-1"
      ]
    }
  ],
  "aliases": [],
  "details": "pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.4, the BER decoder shared by the CER and DER codecs parses long-form tags by accumulating continuation octets without an upper bound on the tag ID size, allowing a crafted input to force construction of an arbitrarily large integer with CPU cost growing quadratically and to trigger unhandled ValueError exceptions in Python 3.11+ error formatting paths. Any application decoding untrusted BER, CER, or DER input is affected. This issue is fixed in version 0.6.4.",
  "id": "UBUNTU-CVE-2026-59884",
  "modified": "2026-07-14T17:17:00Z",
  "published": "2026-07-14T17:17:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-59884"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-59884"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/pyasn1/pyasn1/security/advisories/GHSA-m4p7-r5rc-7g4j"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/pyasn1/pyasn1/commit/628e36ecbb5277a3f01572ce418ef54271b165a5"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/pyasn1/pyasn1/releases/tag/v0.6.4"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-59884"
  ]
}



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