CVE-2025-24963 is a medium-severity (CVSS 5.9) Path Traversal vulnerability in @vitest/browser. A fix is available for @vitest/browser — see the affected versions and patch details below.
Browser mode serves arbitrary files in vitest
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 CVE-2025-24963.
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-2025-24963 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 377,238 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.
@vitest/browsernpmDescription
Vitest is a testing framework powered by Vite. The __screenshot-error handler on the browser mode HTTP server that responds any file on the file system. Especially if the server is exposed on the network by browser.api.host: true, an attacker can send a request to that handler from remote to get the content of arbitrary files.This __screenshot-error handler on the browser mode HTTP server responds any file on the file system. This code was added by commit 2d62051. Users explicitly exposing the browser mode server to the network by browser.api.host: true may get any files exposed. This issue has been addressed in versions 2.1.9 and 3.0.4. Users are advised to upgrade. There are no known workarounds for this vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @vitest/browser | ≥ 2.0.4&&< 2.1.9 | 2.1.9npm install @vitest/browser@2.1.9 |
| 📦npm | @vitest/browser | ≥ 3.0.0&&< 3.0.4 | 3.0.4npm install @vitest/browser@3.0.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @vitest/browser, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @vitest/browser to 2.1.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-24963 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-2025-24963 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-24963. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
How to detect CVE-2025-24963
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2025-24963 -u https://target- Template
- Vitest Browser Mode - Local File Read
- Severity
- medium
- Impact
- Attackers can read arbitrary files from the file system when the browser mode server is exposed to the network, potentially exposing source code, configuration files, and sensitive credentials.
- Remediation
- Upgrade to Vitest version 2.1.9, 3.0.4 or later that addresses the __screenshot-error handler vulnerability.
Template by ProjectDiscovery nuclei-templates (iamnoooob, rootxharsh, pdresearch), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is CVE-2025-24963 in your dependencies?
O3 Security finds CVE-2025-24963 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.