CVE-2026-41645: CWE-94: Improper Control of Generation of Code ('Code Injection') in projectdiscovery nuclei
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.
AI Analysis
Technical Summary
Nuclei is a vulnerability scanner using a YAML-based DSL. Between versions 3.0.0 and before 3.8.0, its expression evaluation engine improperly controls code generation, allowing a malicious server to inject and execute DSL expressions when HTTP response data containing helper/function syntax is reused in multi-step templates. If the -env-vars / -ev option is enabled, this can disclose host environment variables. The vulnerability is identified as CWE-94 and has a CVSS 3.1 base score of 5.3 (medium severity). The issue was patched in version 3.8.0.
Potential Impact
The vulnerability allows a malicious target server to inject and execute code expressions within Nuclei's DSL evaluation engine. This can lead to information disclosure of host environment variables if the -env-vars / -ev option is enabled. Standard configurations with this option disabled are not affected by the information disclosure risk. There is no indication of integrity or availability impact. No known exploits are reported in the wild.
Mitigation Recommendations
Upgrade Nuclei to version 3.8.0 or later, where this vulnerability is patched. If upgrading immediately is not possible, ensure that the -env-vars / -ev option remains disabled (which is the default) to avoid exposure of host environment variables. Monitor vendor advisories for any additional guidance.
CVE-2026-41645: CWE-94: Improper Control of Generation of Code ('Code Injection') in projectdiscovery nuclei
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.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Nuclei is a vulnerability scanner using a YAML-based DSL. Between versions 3.0.0 and before 3.8.0, its expression evaluation engine improperly controls code generation, allowing a malicious server to inject and execute DSL expressions when HTTP response data containing helper/function syntax is reused in multi-step templates. If the -env-vars / -ev option is enabled, this can disclose host environment variables. The vulnerability is identified as CWE-94 and has a CVSS 3.1 base score of 5.3 (medium severity). The issue was patched in version 3.8.0.
Potential Impact
The vulnerability allows a malicious target server to inject and execute code expressions within Nuclei's DSL evaluation engine. This can lead to information disclosure of host environment variables if the -env-vars / -ev option is enabled. Standard configurations with this option disabled are not affected by the information disclosure risk. There is no indication of integrity or availability impact. No known exploits are reported in the wild.
Mitigation Recommendations
Upgrade Nuclei to version 3.8.0 or later, where this vulnerability is patched. If upgrading immediately is not possible, ensure that the -env-vars / -ev option remains disabled (which is the default) to avoid exposure of host environment variables. Monitor vendor advisories for any additional guidance.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-21T23:58:43.802Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69fd5dbdcbff5d86108b643f
Added to database: 5/8/2026, 3:51:25 AM
Last enriched: 5/8/2026, 4:07:53 AM
Last updated: 5/9/2026, 4:51:14 AM
Views: 6
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