GHSA-529f-9qwm-9628
tinacms is vulnerable to arbitrary code execution
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
tinacmsnpm@tinacms/clinpmDescription
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
- Create a tinacms app using the cli/documentation:
npx create-tina-app@latest
- Modify one of the blog posts to contain the following front matter:
---js
{
"title": "Pawned" + console.log(require("fs").readFileSync("/etc/passwd").toString())
}
---
- Start the tinacms server, e.g., with
npm run dev - 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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | tinacms | all versions | 3.1.1 |
| 📦npm | @tinacms/cli | all versions | 2.0.4 |
| 📦npm | @tinacms/graphql | all versions | 2.0.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tinacms. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update tinacms to 3.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-529f-9qwm-9628 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-529f-9qwm-9628 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-529f-9qwm-9628. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-529f-9qwm-9628 in your dependencies?
O3 detects GHSA-529f-9qwm-9628 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.