GHSA-529F-9QWM-9628

Vulnerability from github – Published: 2025-12-18 18:45 – Updated: 2025-12-18 18:45
VLAI?
Summary
tinacms is vulnerable to arbitrary code execution
Details

Summary

tinacms uses the gray-matter package in an insecure way allowing attackers that can control the content of the processed markdown files, e.g., blog posts, to execute arbitrary code.

Details

The gray-matter package executes by default the code in the markdown file's front matter. tinacms does not change this behavior when process markdown file, e.g., by passing a custom engine property for js/javascript in the options object.

PoC

  1. Create a tinacms app using the cli/documentation: 
npx create-tina-app@latest
  1. Modify one of the blog posts to contain the following front matter:
---js
{
  "title": "Pawned" + console.log(require("fs").readFileSync("/etc/passwd").toString())
}
---
  1. Start the tinacms server, e.g., with npm run dev
  2. Observe the console of the server printing the password file, showing that attackers can execute arbitrary commands.

Impact

RCE: attackers can execute arbitrary JavaScript code on the server hosting tinacms.

Feasibility

Potential attack scenarios can be executed like this: Companies often have technical writers as contractors. These contractors produce md files, which they send over email or upload in a shared cloud folder. Developers download these files and upload them in tinacms's content folder. While this example might appear speculative or contrived, a general observation is that developers would be very surprised to find out that processing untrusted markdown files via tinacms = server-side code execution = complete machine take over. That is, tinacms users might not expect markdown files to contain anything else than data and gray-matter violates that assumption.

Severity ?
7.3 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "tinacms"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.1.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "@tinacms/cli"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.0.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "@tinacms/graphql"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.0.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2025-68278"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-94"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2025-12-18T18:45:41Z",
    "nvd_published_at": "2025-12-18T16:15:57Z",
    "severity": "HIGH"
  },
  "details": "### Summary\n```tinacms``` uses the ```gray-matter``` package in an insecure way allowing attackers that can control the content of the processed markdown files, e.g., blog posts, to execute arbitrary code.\n\n### Details\nThe ```gray-matter``` package executes by default the code in the markdown file\u0027s front matter. ```tinacms``` does not change this behavior when process markdown file, e.g., by passing a custom engine property for js/javascript in the options object.\n\n### PoC\n1. Create a tinacms app using the cli/documentation: \n```\nnpx create-tina-app@latest\n```\n2. Modify one of the blog posts to contain the following front matter:\n```js\n---js\n{\n  \"title\": \"Pawned\" + console.log(require(\"fs\").readFileSync(\"/etc/passwd\").toString())\n}\n---\n```\n3. Start the tinacms server, e.g., with ```npm run dev```\n4. Observe the console of the server printing the password file, showing that attackers can execute arbitrary commands. \n\n### Impact\nRCE: attackers can execute arbitrary JavaScript code on the server hosting tinacms.\n\n### Feasibility\nPotential attack scenarios can be executed like this: Companies often have technical writers as contractors. These contractors produce md files, which they send over email or upload in a shared cloud folder. Developers download these files and upload them in ```tinacms```\u0027s content folder. While this example might appear speculative or contrived, a general observation is that developers would be very surprised to find out that processing untrusted markdown files via ```tinacms``` = server-side code execution = complete machine take over. That is, ```tinacms``` users might not expect markdown files to contain anything else than data and ```gray-matter``` violates that assumption.",
  "id": "GHSA-529f-9qwm-9628",
  "modified": "2025-12-18T18:45:41Z",
  "published": "2025-12-18T18:45:41Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/tinacms/tinacms/security/advisories/GHSA-529f-9qwm-9628"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-68278"
    },
    {
      "type": "WEB",
      "url": "https://github.com/tinacms/tinacms/commit/fa7c27abef968e3f3a3e7d564f282bc566087569"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/tinacms/tinacms"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P",
      "type": "CVSS_V4"
    }
  ],
  "summary": "tinacms is vulnerable to arbitrary code execution"
}


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