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.

Published: 2026-05-08T03:17:19.302Z
Updated: 2026-05-11T18:16:02.582Z

ProjectDiscovery Nuclei 3 before 3.8.0 allows DSL expression injection. This affects use of -env-vars for multi-step templates against untrusted targets (not the default configuration).

Published: 2026-04-20T07:10:30.246Z
Updated: 2026-04-21T00:59:19.998Z

Nuclei is a vulnerability scanner powered by YAML based templates. Starting in version 3.0.0 and prior to version 3.3.2, a vulnerability in Nuclei's template signature verification system could allow an attacker to bypass the signature check and possibly execute malicious code via custom code template. The vulnerability is present in the template signature verification process, specifically in the `signer` package. The vulnerability stems from a discrepancy between how the signature verification process and the YAML parser handle newline characters, combined with the way multiple signatures are processed. This allows an attacker to inject malicious content into a template while maintaining a valid signature for the benign part of the template. CLI users are affected if they execute custom code templates from unverified sources. This includes templates authored by third parties or obtained from unverified repositories. SDK Users are affected if they are developers integrating Nuclei into their platforms, particularly if they permit the execution of custom code templates by end-users. The vulnerability is addressed in Nuclei v3.3.2. Users are strongly recommended to update to this version to mitigate the security risk. As an interim measure, users should refrain from using custom templates if unable to upgrade immediately. Only trusted, verified templates should be executed. Those who are unable to upgrade Nuclei should disable running custom code templates as a workaround.

Published: 2024-09-04T15:36:23.277Z
Updated: 2024-09-04T16:21:54.357Z

Nuclei is a vulnerability scanner. Prior to version 2.9.9, a security issue in the Nuclei project affected users utilizing Nuclei as Go code (SDK) running custom templates. This issue did not affect CLI users. The problem was related to sanitization issues with payload loading in sandbox mode. There was a potential risk with payloads loading in sandbox mode. The issue occurred due to relative paths not being converted to absolute paths before doing the check for `sandbox` flag allowing arbitrary files to be read on the filesystem in certain cases when using Nuclei from `Go` SDK implementation. This issue has been fixed in version 2.9.9. The maintainers have also enabled sandbox by default for filesystem loading. This can be optionally disabled if required. The `-sandbox` option has been deprecated and is now divided into two new options: `-lfa` (allow local file access) which is enabled by default and `-lna` (restrict local network access) which can be enabled by users optionally. The `-lfa` allows file (payload) access anywhere on the system (disabling sandbox effectively), and `-lna` blocks connections to the local/private network.

Published: 2023-08-04T15:34:11.804Z
Updated: 2024-10-08T18:13:54.292Z