Is CVE-2026-76805 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-76805 being exploited in the wild.

How severe is CVE-2026-76805?

Medium severity, with a CVSS score of 5.3, published 22 September 2026.

Which products and versions are affected?

github.com/projectdiscovery/nuclei (Go) SEMVER:introduced=0; github.com/projectdiscovery/nuclei/v2 (Go) SEMVER:introduced=0; github.com/projectdiscovery/nuclei/v3 (Go) >= 3.0.0, < 3.10.0, SEMVER:introduced=3.0.0,fixed=3.10.0.

Is there a fix for CVE-2026-76805?

Yes. github.com/projectdiscovery/nuclei/v3 (Go): upgrade to 3.10.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-76805 attacked?

It is attacked over the network.

Am I affected by CVE-2026-76805?

Check whether you run github.com/projectdiscovery/nuclei (Go), github.com/projectdiscovery/nuclei/v2 (Go) or github.com/projectdiscovery/nuclei/v3 (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-76805: Nuclei environment variable disclosure in DAST/Fuzz mode

Q: Is there a fix for CVE-2026-76805?

Yes. github.com/projectdiscovery/nuclei/v3 (Go): upgrade to 3.10.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-76805 attacked?

It is attacked over the network.

Q: Am I affected by CVE-2026-76805?

Check whether you run github.com/projectdiscovery/nuclei (Go), github.com/projectdiscovery/nuclei/v2 (Go) or github.com/projectdiscovery/nuclei/v3 (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-76805 · Severity: medium · CVSS 5.3 · Published 2026-09-22

Nuclei is a vulnerability scanner used by security teams to automate security testing. When scanning untrusted web targets with the environment variable flag enabled, a malicious server can trick Nuclei into exposing sensitive host environment variables (such as API keys, credentials, and tokens) through response data that gets reinterpreted as template syntax. This exposure only occurs when users explicitly enable the environment variable feature, which is off by default.

Technologies: github.com/projectdiscovery/nuclei (Go), github.com/projectdiscovery/nuclei/v2 (Go), github.com/projectdiscovery/nuclei/v3 (Go). Vendors: Go.

Quick answers

Is CVE-2026-76805 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-76805 being exploited in the wild.
How severe is CVE-2026-76805?: Medium severity, with a CVSS score of 5.3, published 22 September 2026.
Which products and versions are affected?: github.com/projectdiscovery/nuclei (Go) SEMVER:introduced=0; github.com/projectdiscovery/nuclei/v2 (Go) SEMVER:introduced=0; github.com/projectdiscovery/nuclei/v3 (Go) >= 3.0.0, < 3.10.0, SEMVER:introduced=3.0.0,fixed=3.10.0.
Is there a fix for CVE-2026-76805?: Yes. github.com/projectdiscovery/nuclei/v3 (Go): upgrade to 3.10.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-76805 attacked?: It is attacked over the network.
Am I affected by CVE-2026-76805?: Check whether you run github.com/projectdiscovery/nuclei (Go), github.com/projectdiscovery/nuclei/v2 (Go) or github.com/projectdiscovery/nuclei/v3 (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

github.com/projectdiscovery/nuclei/v3 (Go): upgrade to 3.10.0 or later
```
go get github.com/projectdiscovery/nuclei/v3@v3.10.0
```

Technical details

The vulnerability exists in Nuclei's DAST/fuzz payload evaluation pipeline (pkg/fuzz/parts.go) where response-derived data captured by internal extractors is evaluated multiple times instead of once. When the `-env-vars` / `-ev` flag is enabled, environment variables are merged into the template variable map. A malicious target can return response data containing expressions like `{{env_var_name}}` which, when reused in a subsequent fuzz step as substituted content, are re-evaluated and resolve to actual environment variable values. The root cause is that the previous CVE-2026-41645 fix enforced single-pass evaluation within one call but did not address callers that invoke evaluation multiple times on substituted output. The vulnerability requires multi-step templates chaining internal extractors into fuzz steps and the explicit `-ev` flag. The fix in Nuclei v3.10.0 ensures template text is rendered once through a shared rendering boundary.

Affected products

Project Discovery Nuclei before 3.10.0

Identifiers

CVE-2026-76805
GHSA-jpvm-9frm-hjcq
GO-2026-6571

Timeline

2026-09-22: disclosed
2026-09-22: patched: Fixed in Nuclei v3.10.0
2025-12-30: other: Original CVE-2026-41645 fix attempt

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