CVE-2026-41646 is a medium-severity (CVSS 5.5) CWE-284 vulnerability in github.com/projectdiscovery/nuclei/v3. A fix is available for github.com/projectdiscovery/nuclei/v3 — see the affected versions and patch details below.
Nuclei: Local File Read via require() Module Loader Bypass
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-2026-41646.
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-2026-41646 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
github.com/projectdiscovery/nuclei/v3Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
A vulnerability in Nuclei's JavaScript protocol runtime allows JavaScript templates to read local .js and .json files through the require() function, bypassing the default local file access restriction.
Affected Component
The issue is in the JavaScript runtime's module loading system. The goja require() function used a default host filesystem loader without routing through the allow-local-file-access check.
Description
The goja require() function in Nuclei's JavaScript protocol runtime used the default host filesystem loader, which allowed JavaScript templates to import .js and .json files from anywhere on the host filesystem, ignoring the allow-local-file-access (-lfa) option that controls file access outside the template directory.
The impact is limited to .js and .json files, as goja's module loader only resolves those extensions. That said, this is still enough to expose sensitive data stored in JSON configuration files like package.json, credential stores, or cloud configuration files sitting on the host filesystem.
Affected Users
- CLI users running untrusted or third-party JavaScript templates.
- SDK users who have integrated Nuclei into platforms where end-users can supply JavaScript templates, especially when relying on the default file access restriction to limit filesystem reads.
[!NOTE] The
require()module loader only resolves.jsand.jsonfiles. Other file types cannot be read through this vector.
Patches
- The vulnerability is fixed in Nuclei v3.8.0. Upgrading is strongly recommended.
- Fix reference: #7332
Mitigation
Upgrade to Nuclei v3.8.0, where the require() registry is rebuilt per execution and file-backed module loads are routed through the same allow-local-file-access check as the rest of the filesystem operations.
In the meantime, avoid running JavaScript templates from unverified sources.
Workarounds
If upgrading is not an option, avoid running untrusted JavaScript templates entirely. There is no flag or configuration that mitigates this on affected versions.
Acknowledgments
Nuceli thanks @AkashHamal0x01 for reporting this issue through responsible disclosure via [email protected]
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/projectdiscovery/nuclei/v3 | ≥ 3.0.0&&< 3.8.0 | 3.8.0go get github.com/projectdiscovery/nuclei/v3@v3.8.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/projectdiscovery/nuclei/v3, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/projectdiscovery/nuclei/v3 to 3.8.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-41646 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-2026-41646 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-41646. 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-2026-41646 in your dependencies?
O3 Security finds CVE-2026-41646 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.