GHSA-FXGQ-9M89-CXJ9

Vulnerability from github – Published: 2026-08-25 18:23 – Updated: 2026-08-25 18:23
VLAI
Summary
eml_parser has a URL extraction bypass via HTML entities in URLs
Details

Summary

eml_parser performs certain validations on potential URL strings to discard bogus values. In versions prior to 3.0.2, this validation was performed before unescaping any HTML entities that might occur in the string. This caused the library to wrongfully reject valid URLs that use HTML entities for the :, /, or . characters. These URLs would then not be included in the list of extracted URLs. Similarly, the host parts of such URLs would not be extracted.

For example, neither the URL https://phishing.example.com nor its host (phishing.example.com) would appear in the parsing result.

Impact

eml_parser is used in email security gateways and SOC pipelines to extract URLs as IOCs. Those URLs are then checked against threat-intel feeds, URL reputation services, and sandboxes. A URL that is not extracted is never checked.

Patches

Since version 3.0.2 the library unescapes all HTML entities in every URL before deciding to accept or reject it. A test was added to prevent regressions.

Severity
6.5 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "eml_parser"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.0.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-55618"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-116"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-08-25T18:23:16Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "## Summary\n\n`eml_parser` performs certain validations on potential URL strings to discard bogus values. In versions prior to `3.0.2`, this validation was performed before unescaping any HTML entities that might occur in the string. This caused the library to wrongfully reject valid URLs that use HTML entities for the `:`, `/`, or `.` characters. These URLs would then not be included in the list of extracted URLs. Similarly, the host parts of such URLs would not be extracted.\n\nFor example, neither the URL `https\u0026#58;\u0026#47;\u0026#47;phishing\u0026#46;example\u0026#46;com` nor its host (`phishing.example.com`) would appear in the parsing result.\n\n## Impact\n\n`eml_parser` is used in email security gateways and SOC pipelines to extract URLs as IOCs. Those URLs are then checked against threat-intel feeds, URL reputation services, and sandboxes. A URL that is not extracted is never checked.\n\n## Patches\n\nSince version 3.0.2 the library unescapes all HTML entities in every URL before deciding to accept or reject it. A test was added to prevent regressions.",
  "id": "GHSA-fxgq-9m89-cxj9",
  "modified": "2026-08-25T18:23:16Z",
  "published": "2026-08-25T18:23:16Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/GOVCERT-LU/eml_parser/security/advisories/GHSA-fxgq-9m89-cxj9"
    },
    {
      "type": "WEB",
      "url": "https://github.com/GOVCERT-LU/eml_parser/pull/90"
    },
    {
      "type": "WEB",
      "url": "https://github.com/GOVCERT-LU/eml_parser/commit/746a69f86443eb0b6a47f77db3cfe727c21f92b3"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/GOVCERT-LU/eml_parser"
    },
    {
      "type": "WEB",
      "url": "https://github.com/GOVCERT-LU/eml_parser/releases/tag/v3.0.2"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "eml_parser has a URL extraction bypass via HTML entities in URLs"
}



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.


Detection rules are retrieved from Rulezet.