BREW-FONTTOOLS-CVE-2023-45139 (CVE-2023-45139)

Vulnerability from osv_homebrew – Published: 2026-08-13 16:48 – Updated: 2026-09-25 10:27 – Source website
VLAI
Summary
fonttools XML External Entity Injection (XXE) Vulnerability
Details

fontTools is a library for manipulating fonts, written in Python. The subsetting module has a XML External Entity Injection (XXE) vulnerability which allows an attacker to resolve arbitrary entities when a candidate font (OT-SVG fonts), which contains a SVG table, is parsed. This allows attackers to include arbitrary files from the filesystem fontTools is running on or make web requests from the host system. This vulnerability has been patched in version 4.43.0.

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

{
  "affected": [
    {
      "ecosystem_specific": {
        "fix": "bump",
        "range_state": "fixed",
        "upstream_fixed_in": "4.43.0"
      },
      "package": {
        "ecosystem": "Homebrew",
        "name": "fonttools",
        "purl": "pkg:brew/fonttools"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.63.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "confidence": "high",
    "source": "matched",
    "strategy": "git",
    "upstream_evidence": [
      {
        "ecosystem": "GIT",
        "key": "https://github.com/fonttools/fonttools",
        "name": "https://github.com/fonttools/fonttools",
        "strategy": "git",
        "subject_version": "4.66.0"
      },
      {
        "ecosystem": "PyPI",
        "key": "pkg:pypi/fonttools@4.66.0",
        "name": "fonttools",
        "strategy": "registry",
        "subject_version": "4.66.0"
      },
      {
        "ecosystem": "Debian",
        "key": "Debian/fonttools",
        "name": "fonttools",
        "strategy": "distro"
      },
      {
        "ecosystem": "GIT",
        "key": "upstream:https://github.com/fonttools/fonttools",
        "name": "https://github.com/fonttools/fonttools",
        "strategy": "distro",
        "subject_version": "4.66.0"
      },
      {
        "ecosystem": "PyPI",
        "key": "upstream:pkg:pypi/fonttools@4.66.0",
        "name": "fonttools",
        "strategy": "distro",
        "subject_version": "4.66.0"
      },
      {
        "ecosystem": "Ubuntu",
        "key": "Ubuntu/fonttools",
        "name": "fonttools",
        "strategy": "distro"
      }
    ]
  },
  "details": "fontTools is a library for manipulating fonts, written in Python. The subsetting module has a XML External Entity Injection (XXE) vulnerability which allows an attacker to resolve arbitrary entities when a candidate font (OT-SVG fonts), which contains a SVG table, is parsed. This allows attackers to include arbitrary files from the filesystem fontTools is running on or make web requests from the host system. This vulnerability has been patched in version 4.43.0.",
  "id": "BREW-fonttools-CVE-2023-45139",
  "modified": "2026-09-25T10:27:40Z",
  "published": "2026-08-13T16:48:19Z",
  "references": [
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2024/03/08/2"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2024/03/09/1"
    },
    {
      "type": "WEB",
      "url": "https://github.com/fonttools/fonttools/releases/tag/4.43.0"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VY63B4SGY4QOQGUXMECRGD6K3YT3GJ75/"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/45xxx/CVE-2023-45139.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/fonttools/fonttools/security/advisories/GHSA-6673-4983-2vx5"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-45139"
    },
    {
      "type": "FIX",
      "url": "https://github.com/fonttools/fonttools/commit/9f61271dc1ca82ed91f529b130fe5dc5c9bf1f4c"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "fonttools XML External Entity Injection (XXE) Vulnerability",
  "upstream": [
    "CVE-2023-45139",
    "GHSA-6673-4983-2vx5",
    "PYSEC-2026-1388"
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.