{"id":"CVE-2026-76805","published":"2026-09-22T16:48:49Z","modified":"2026-09-22T18:19:16Z","title":"Nuclei: Environment Variable Disclosure via Response-Derived Data in DAST/Fuzz Mode","vendor":"projectdiscovery","product":"nuclei","tier":"tail","description":{"text":"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.","provenance":"source","from":"CVE.org"},"cvss":{"score":5.3,"severity":"MEDIUM","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N","provenance":"source","from":"CVE.org CNA"},"epss":{"score":0.0041,"percentile":0.35171,"provenance":"source"},"cwes":[{"id":"CWE-200","name":"Exposure of Sensitive Information to an Unauthorized Actor"}],"references":[{"url":"https://github.com/projectdiscovery/nuclei/security/advisories/GHSA-jpvm-9frm-hjcq","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/projectdiscovery/nuclei/pull/7499","tags":["x_refsource_MISC"]},{"url":"https://github.com/projectdiscovery/nuclei/commit/ccbfb12bd01447ba25f6e755dfb2bee677736da6","tags":["x_refsource_MISC"]},{"url":"https://github.com/projectdiscovery/nuclei/releases/tag/v3.10.0","tags":["x_refsource_MISC"]}],"priority":{"score":10.7,"factors":[{"name":"EPSS percentile","points":7.03},{"name":"CVSS severity","points":3.71}]},"vendorSlug":"projectdiscovery","affectedVersions":[{"vendor":"projectdiscovery","product":"nuclei","versions":[">= 3.0.0, < 3.10.0"]}],"affected":[{"ecosystem":"Go","package":"github.com/projectdiscovery/nuclei/v3","vulnerableRanges":[">=3.0.0, <3.10.0"],"patched":["3.10.0"],"from":["GHSA-jpvm-9frm-hjcq","GO-2026-6571"],"provenance":"source"},{"ecosystem":"Go","package":"github.com/projectdiscovery/nuclei","vulnerableRanges":["all versions"],"patched":[],"from":["GO-2026-6571"],"provenance":"source"},{"ecosystem":"Go","package":"github.com/projectdiscovery/nuclei/v2","vulnerableRanges":["all versions"],"patched":[],"from":["GO-2026-6571"],"provenance":"source"}],"euvd":{"id":"EUVD-2026-84557","exploited":false,"provenance":"source"},"lineage":{"familyId":"fam-projectdiscovery-nuclei-cve-2026-41282","parents":[{"from":"CVE-2026-41645","to":"CVE-2026-76805","relation":"incomplete-fix","confidence":"high","kind":"lineage","evidence":[{"kind":"text","provenance":"source","relation":"incomplete-fix","quote":"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.","from":"CVE.org","in":"CVE-2026-76805"}]}]}}