# CVE-2026-41645: Nuclei: Environment variable disclosure via Response-Derived DSL Expressions

> A malicious server can inject DSL expressions in Nuclei to disclose host environment variables if the non-default environment variable option is enabled.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 8 May 2026
- **Updated:** 11 May 2026

## What is CVE-2026-41645?

CVE-2026-41645 is a medium-severity code injection vulnerability in projectdiscovery nuclei, published on 8 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Nuclei is a vulnerability scanner built on a simple YAML-based DSL. From version 3.0.0 to before version 3.8.0, a vulnerability in Nuclei's expression evaluation engine makes it possible for a malicious target server to inject and execute supported DSL expressions. This happens when HTTP response data containing helper/function syntax gets reused by multi-step templates. If the -env-vars / -ev option is explicitly enabled, this can expose host environment variables. That option is off by default, so standard configurations are not affected by the information disclosure risk. This issue has been patched in version 3.8.0.

Weakness: CWE-94 (Improper Control of Generation of Code)

## Which versions are affected by CVE-2026-41645?

It affects 1 product.


Products: Projectdiscovery Nuclei.

## How do I fix CVE-2026-41645?

Upgrade to a fixed version.

## Is CVE-2026-41645 being exploited?

There is no known exploitation of CVE-2026-41645 in the wild and no public exploit code.

## Other vulnerabilities in projectdiscovery nuclei

- [CVE-2023-37896](https://insights.sbomify.com/CVE-2023-37896/): Nuclei Path Traversal vulnerability (high 7.5)
- [CVE-2024-43405](https://insights.sbomify.com/CVE-2024-43405/): Nuclei Template Signature Verification Bypass (high 7.4)
- [CVE-2024-27920](https://insights.sbomify.com/CVE-2024-27920/): Unsigned code template execution through workflows in projectdiscovery/nuclei (high 7.4)
- [CVE-2026-41646](https://insights.sbomify.com/CVE-2026-41646/): Nuclei: Local File Read via require() Module Loader Bypass (medium 5.5)
- [CVE-2026-41282](https://insights.sbomify.com/CVE-2026-41282/): Code injection in Nuclei (medium 4.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-41645 and fix it if it is affected.

What it is: CVE-2026-41645 is a medium-severity code injection vulnerability in projectdiscovery nuclei, published on 8 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-41645 in the wild and no public exploit code.

Affected product: projectdiscovery nuclei. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-41645/ (Markdown: https://insights.sbomify.com/CVE-2026-41645/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-41645
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-41645
- OSV: https://osv.dev/vulnerability/CVE-2026-41645

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-41645/
Summaries are generated and may contain mistakes; the official description above is the record.