CVE-2026-33768 is a medium-severity (CVSS 6.5) vulnerability in @astrojs/vercel. A fix is available for @astrojs/vercel — see the affected versions and patch details below.
Astro: Unauthenticated Path Override via `x-astro-path` / `x_astro_path`
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.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-33768.
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-2026-33768 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 377,333 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
@astrojs/vercelReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.
Description
Astro is a web framework. Prior to version 10.0.2, the @astrojs/vercel serverless entrypoint reads the x-astro-path header and x_astro_path query parameter to rewrite the internal request path, with no authentication whatsoever. On deployments without Edge Middleware, this lets anyone bypass Vercel's platform-level path restrictions entirely. The override preserves the original HTTP method and body, so this isn't limited to GET. POST, PUT, DELETE all land on the rewritten path. A Firewall rule blocking /admin/* does nothing when the request comes in as POST /api/health?x_astro_path=/admin/delete-user. This issue has been patched in version 10.0.2.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @astrojs/vercel | all versions | 10.0.2npm install @astrojs/vercel@10.0.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @astrojs/vercel, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @astrojs/vercel to 10.0.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33768 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-2026-33768 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-33768. 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-2026-33768 in your dependencies?
O3 Security finds CVE-2026-33768 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.