ubuntu-cve-2021-44686
Vulnerability from osv_ubuntu
Published
2021-12-07 00:15
Modified
2026-05-20 14:53
Summary
Details

calibre before 5.32.0 contains a regular expression that is vulnerable to ReDoS (Regular Expression Denial of Service) in html_preprocess_rules in ebooks/conversion/preprocess.py.

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)
low
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "calibre",
            "binary_version": "2.55.0+dfsg-1ubuntu0.2"
          },
          {
            "binary_name": "calibre-bin",
            "binary_version": "2.55.0+dfsg-1ubuntu0.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:16.04:LTS",
        "name": "calibre",
        "purl": "pkg:deb/ubuntu/calibre@2.55.0+dfsg-1ubuntu0.2?arch=source\u0026distro=xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.33.0+dfsg-1build1",
        "2.38.0+dfsg-1",
        "2.45.0+dfsg-1",
        "2.45.0+dfsg-1build1",
        "2.48.0+dfsg-1",
        "2.48.0+dfsg-1build1",
        "2.54.0+dfsg-1",
        "2.55.0+dfsg-1",
        "2.55.0+dfsg-1ubuntu0.2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "calibre",
            "binary_version": "3.21.0+dfsg-1build1"
          },
          {
            "binary_name": "calibre-bin",
            "binary_version": "3.21.0+dfsg-1build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "calibre",
        "purl": "pkg:deb/ubuntu/calibre@3.21.0+dfsg-1build1?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.7.0+dfsg-2",
        "3.7.0+dfsg-2build1",
        "3.12.0+dfsg-1",
        "3.13.0+dfsg-1",
        "3.14.0+dfsg-1",
        "3.15.0.1+dfsg-1",
        "3.16.0+dfsg-1",
        "3.16.0+dfsg-1build1",
        "3.17.0+dfsg-1",
        "3.17.0+dfsg-2",
        "3.18.0+dfsg-1build1",
        "3.19.0+dfsg-1",
        "3.20.0+dfsg-1",
        "3.21.0+dfsg-1",
        "3.21.0+dfsg-1build1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "calibre",
            "binary_version": "4.99.4+dfsg+really4.12.0-1ubuntu1"
          },
          {
            "binary_name": "calibre-bin",
            "binary_version": "4.99.4+dfsg+really4.12.0-1ubuntu1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "calibre",
        "purl": "pkg:deb/ubuntu/calibre@4.99.4+dfsg+really4.12.0-1ubuntu1?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.46.0+dfsg-1",
        "4.2.0+dfsg-2",
        "4.3.0+dfsg-1",
        "4.3.0+dfsg-2",
        "4.4.0+dfsg-1",
        "4.5.0+dfsg-1",
        "4.5.0+dfsg-2",
        "4.5.0+dfsg-3",
        "4.6.0+dfsg-1",
        "4.7.0+dfsg-1",
        "4.99.3+dfsg-2",
        "4.99.4+dfsg-1",
        "4.99.4+dfsg-1build1",
        "4.99.4+dfsg+really4.10.0+py3-2",
        "4.99.4+dfsg+really4.11.2-1",
        "4.99.4+dfsg+really4.11.2-1build1",
        "4.99.4+dfsg+really4.12.0-1",
        "4.99.4+dfsg+really4.12.0-1build1",
        "4.99.4+dfsg+really4.12.0-1ubuntu1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "calibre",
            "binary_version": "5.37.0+dfsg-1build1"
          },
          {
            "binary_name": "calibre-bin",
            "binary_version": "5.37.0+dfsg-1build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "calibre",
        "purl": "pkg:deb/ubuntu/calibre@5.37.0+dfsg-1build1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "5.25.0+dfsg-2",
        "5.33.2+dfsg-1",
        "5.34.0+dfsg-1",
        "5.35.0+dfsg-1ubuntu2",
        "5.37.0+dfsg-1",
        "5.37.0+dfsg-1build1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "calibre",
            "binary_version": "9.2.1+ds+~0.10.5-2build1"
          },
          {
            "binary_name": "calibre-bin",
            "binary_version": "9.2.1+ds+~0.10.5-2build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "calibre",
        "purl": "pkg:deb/ubuntu/calibre@9.2.1+ds+~0.10.5-2build1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "8.8.0+ds-3build1",
        "8.13.0+ds+~0.10.5-3",
        "8.14.0+ds+~0.10.5-1",
        "8.15.0+ds+~0.10.5-1",
        "8.16.0+ds+~0.10.5-2",
        "8.16.2+ds+~0.10.5-1",
        "8.16.2+ds+~0.10.5-2",
        "8.16.2+ds+~0.10.5-3",
        "9.2.1+ds+~0.10.5-2build1"
      ]
    }
  ],
  "aliases": [],
  "details": "calibre before 5.32.0 contains a regular expression that is vulnerable to ReDoS (Regular Expression Denial of Service) in html_preprocess_rules in ebooks/conversion/preprocess.py.",
  "id": "UBUNTU-CVE-2021-44686",
  "modified": "2026-05-20T14:53:37Z",
  "published": "2021-12-07T00:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-44686"
    },
    {
      "type": "REPORT",
      "url": "https://bugs.launchpad.net/calibre/+bug/1951979"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/dwisiswant0/advisory/issues/18"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/kovidgoyal/calibre/compare/v5.31.1...v5.32.0"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2021-44686"
    }
  ],
  "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": "low",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2021-44686"
  ]
}



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