CVE-2024-36858 is a critical-severity (CVSS 9.8) Unrestricted File Upload vulnerability in @janhq/core. 1 public exploit reference exists, so weaponization risk is real. No vendor fix is recorded yet; mitigation options are listed below.
Jan path traversal vulnerability
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.
- 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-2024-36858.
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-2024-36858 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 377,636 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.
@janhq/corenpmDescription
An arbitrary file upload vulnerability in the /v1/app/writeFileSync interface of Jan v0.4.12 allows attackers to execute arbitrary code via uploading a crafted file. @janhq/core has been deprecated in favor of janhq/jan, this vulnerability has been patched there in v0.5.2.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @janhq/core | all versions | No fix |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @janhq/core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of @janhq/core has shipped for CVE-2024-36858 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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-2024-36858 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2024-36858. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
How to detect CVE-2024-36858
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2024-36858 -u https://target- Template
- Jan v0.4.12 - Arbitrary File Upload
- Severity
- critical
- Impact
- Unauthenticated attackers can upload crafted files to execute arbitrary code on the server.
- Remediation
- Update Jan to a version later than v0.4.12 that patches the arbitrary file upload vulnerability.
Template by ProjectDiscovery nuclei-templates (pussycat0x), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is CVE-2024-36858 in your dependencies?
O3 Security finds CVE-2024-36858 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.