CVE-2026-63123 is a medium-severity (CVSS 6.5) Cross-Site Request Forgery (CSRF) vulnerability in @tinacms/cli. O3 Security confirms whether CVE-2026-63123 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Tina: Cross-origin `POST /media/upload/*` requests can write arbitrary files into the Tina dev server media root
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/clinpmDescription
Tina is a headless content management system. Prior to 2.5.2, the TinaCMS CLI package's Vite dev server packages/@tinacms/cli/src/next/vite/cors.ts origin callback returns false for a disallowed origin but does not reject the request, and packages/@tinacms/cli/src/next/vite/plugins.ts still routes POST /media/upload/* to mediaRouter.handlePost. The upload code in packages/@tinacms/cli/src/next/commands/dev-command/server/media.ts writes attacker-controlled multipart contents inside the configured media root. A remote attacker can cause a developer's browser to submit this state-changing request by inducing the developer to visit an attacker-controlled page while tinacms dev is running. This issue is fixed in version 2.5.2.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @tinacms/cli | all versions | 2.5.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @tinacms/cli. 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/cli to 2.5.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-63123 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 CVE-2026-63123 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 CVE-2026-63123. 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-2026-63123 in your dependencies?
O3 detects CVE-2026-63123 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.