{
  "affected": [
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "phlex"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.4.0.beta1"
            },
            {
              "fixed": "2.4.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "phlex"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.3.0"
            },
            {
              "fixed": "2.3.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "phlex"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.2.0"
            },
            {
              "fixed": "2.2.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "phlex"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.1.0"
            },
            {
              "fixed": "2.1.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "phlex"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.0.0.beta1"
            },
            {
              "fixed": "2.0.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "phlex"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.11.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-02-06T19:35:09Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Impact\n\nDuring a security audit conducted with Claude Opus 4.6 and GPT-5.3-Codex, we identified three specific ways to bypass the XSS (cross-site-scripting) protection built into Phlex.\n\n1. The first bypass could happen if user-provided attributes with string keys were splatted into HTML tag, e.g. `div(**user_attributes)`.\n2. The second bypass could happen if user-provided tag names were passed to the `tag` method, e.g. `tag(some_tag_name_from_user)`.\n3. The third bypass could happen if user\u2019s links were passed to `href` attributes, e.g. `a(href: user_provided_link)`.\n\nAll three of these patterns are meant to be safe and all have now been patched.\n\n### Patches\n\nPhlex has patched all three issues and introduced new tests that run against Safari, Firefox and Chrome.\n\nThe patched versions are:\n\n- [2.4.1](https://rubygems.org/gems/phlex/versions/2.4.1)\n- [2.3.2](https://rubygems.org/gems/phlex/versions/2.3.2)\n- [2.2.2](https://rubygems.org/gems/phlex/versions/2.2.2)\n- [2.1.3](https://rubygems.org/gems/phlex/versions/2.1.3)\n- [2.0.2](https://rubygems.org/gems/phlex/versions/2.0.3)\n- [1.11.1](https://rubygems.org/gems/phlex/versions/1.11.1)\n\nPhlex has also patched the [`main`](https://github.com/yippee-fun/phlex) branch in GitHub.\n\n### Workarounds\nIf a project uses a secure CSP (content security policy) or if the application doesn\u2019t use any of the above patterns, it is not at risk.",
  "id": "GHSA-w67g-2h6v-vjgq",
  "modified": "2026-02-06T19:35:09Z",
  "published": "2026-02-06T19:35:09Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/yippee-fun/phlex/security/advisories/GHSA-w67g-2h6v-vjgq"
    },
    {
      "type": "WEB",
      "url": "https://github.com/yippee-fun/phlex/commit/1d85da417cb15eb8cb2f54a68d531c9b35d9d03a"
    },
    {
      "type": "WEB",
      "url": "https://github.com/yippee-fun/phlex/commit/556441d5a64ff93f749e8116a05b2d97264468ee"
    },
    {
      "type": "WEB",
      "url": "https://github.com/yippee-fun/phlex/commit/74e3d8610ffabc2cf5f241945e9df4b14dceb97d"
    },
    {
      "type": "WEB",
      "url": "https://github.com/yippee-fun/phlex/commit/9f56ad13bea9a7d6117fdfd510446c890709eeac"
    },
    {
      "type": "WEB",
      "url": "https://github.com/yippee-fun/phlex/commit/fe9ea708672f9fa42526d9b47e1cdc4634860ef1"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/yippee-fun/phlex"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Phlex XSS protection bypass via attribute splatting, dynamic tags, and href values"
}