Vulnerability · Published Sep 22, 2026 · Assigned by GitHub_M
CVE-2026-76805Nuclei: Environment Variable Disclosure via Response-Derived Data in DAST/Fuzz Mode
Medium 5.3
In plain English
A medium-severity information exposure in nuclei from projectdiscovery. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 35% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Nuclei is a vulnerability scanner built on a simple YAML-based DSL. From 3.0.0 until 3.10.0, the DAST/fuzz payload path in pkg/fuzz/parts.go can evaluate substituted runtime data more than once, creating a second evaluation pass that allows response content captured by an internal: true extractor in one protocol step to be reinterpreted as template syntax in a later fuzz step. This vulnerability is an incomplete fix for CVE-2026-41645: the prior remediation made expressions.Evaluate() single-pass within one call but did not prevent DAST/fuzz callers from evaluating substituted output again. When -env-vars is enabled, a malicious scan target can return marker-shaped content that resolves against the template variable map and discloses scanner-host environment variables such as credentials, API keys, or tokens. The vulnerability requires a multi-step DAST or fuzz template, response data reused through an internal extractor, and explicit environment-variable expansion; users who do not enable -env-vars are not affected by the sensitive-information disclosure. This issue is fixed in version 3.10.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/projectdiscovery/nuclei | no fix listed | GO-2026-6571 |
| Go | github.com/projectdiscovery/nuclei/v2 | no fix listed | GO-2026-6571 |
| Go | github.com/projectdiscovery/nuclei/v3 | 3.10.0 | GHSA-jpvm-9frm-hjcq |
| Go | github.com/projectdiscovery/nuclei/v3 | 3.10.0 | GO-2026-6571 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| projectdiscovery | nuclei | >= 3.0.0, < 3.10.0 |
Weakness: CWE-200 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N
References
- https://github.com/projectdiscovery/nuclei/security/advisories/GHSA-jpvm-9frm-hjcq x_refsource_CONFIRM
- https://github.com/projectdiscovery/nuclei/pull/7499 x_refsource_MISC
- https://github.com/projectdiscovery/nuclei/commit/ccbfb12bd01447ba25f6e755dfb2bee677736da6 x_refsource_MISC
- https://github.com/projectdiscovery/nuclei/releases/tag/v3.10.0 x_refsource_MISC