CVE-2026-33949 — @tinacms/graphql
HIGHCVE-2026-33949 is a high-severity (CVSS 8.1) Path Traversal vulnerability in @tinacms/graphql. A fix is available for @tinacms/graphql — see the affected versions and patch details below.
@tinacms/graphql has Path Traversal that leads to overwrite of arbitrary files
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.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-33949.
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.
How urgent is this, really
CVE-2026-33949 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 378,156 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
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.
@tinacms/graphqlnpmDescription
Summary
A Path Traversal vulnerability in @tinacms/graphql allows unauthenticated users to write and overwrite arbitrary files within the project root. This is achieved by manipulating the relativePath parameter in GraphQL mutations. The impact includes the ability to replace critical server configuration files and potentially execute arbitrary commands by sabotaging build scripts.
Details
The vulnerability exists in the path validation logic within @tinacms/graphql. Specifically, the regex-based validation in getValidatedPath fails to recognize backslashes (\) as directory separators on non-Windows platforms (Mac/Linux). An attacker can provide a path like x\..\..\..\package.json, which bypasses the validation check but is subsequently treated as a traversal path during file I/O operations by the underlying fs modules and path normalization utilities.
Incriminated code areas:
- packages/@tinacms/graphql/src/database/bridge/filesystem.ts: assertWithinBase function.
- packages/@tinacms/graphql/src/resolver/index.ts:
getValidatedPathfunction.
PoC
- Start the TinaCMS development server.
- Send a malicious GraphQL mutation to overwrite a project file (e.g., package.json):
curl -X POST http://localhost:4001/graphql \
-H "Content-Type: application/json" \
-d '{"query": "mutation { updateDocument(collection: \"global\", relativePath: \"x\\\\..\\\\..\\\\..\\\\package.json\", params: { global: { header: { name: \"OVERWRITTEN\" } } }) { __typename } }"}'
- Observe that the root package.json has been replaced with the provided payload.
Impact
This is an Arbitrary File Write vulnerability. Any unauthenticated user with network access to the GraphQL API can:
- Overwrite critical server configuration files (e.g., package.json, tsconfig.json).
- Host malicious scripts in the
public/directory for client-side attacks. - Perform Arbitrary Code Execution by modifying build scripts or server-side logic files that are subsequently executed by the environment.
Weaknesses:
- CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
- CWE-73: External Control of File Name or Path
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @tinacms/graphql | all versions | 2.2.2npm install @tinacms/graphql@2.2.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @tinacms/graphql, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @tinacms/graphql to 2.2.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33949 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-33949 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-33949. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-33949 in your dependencies?
O3 Security finds CVE-2026-33949 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.