# CVE-2026-76803: Nuclei: Local File Read via MySQL Client Sandbox Bypass

> Attackers can read arbitrary local files by exploiting a MySQL client sandbox bypass in Nuclei when scanning malicious endpoints with JavaScript templates.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 22 Sep 2026
- **Updated:** 25 Sep 2026
- **Also known as:** GHSA-xhmx-w2j4-rw3q, GO-2026-6577

## What is CVE-2026-76803?

CVE-2026-76803 is a medium-severity path traversal vulnerability in projectdiscovery nuclei, published on 22 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Nuclei is a vulnerability scanner built on a simple YAML-based DSL. From 3.0.0 until 3.10.0, the nuclei/mysql JavaScript library does not enforce the local-file sandbox when a JavaScript template supplies the allowAllFiles MySQL DSN option. An untrusted javascript: template scanning an attacker-controlled MySQL-compatible endpoint can cause the server to issue LOAD DATA LOCAL INFILE requests for arbitrary paths, after which the scanner's MySQL client reads the files and returns their contents to the server even though -allow-local-file-access is disabled. JavaScript templates can run unsigned and without the -code flag on affected versions, and the bypass affects CLI and SDK deployments that accept untrusted templates. This issue is fixed in version 3.10.0.

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2026-76803?

5 open source packages ship an affected version, including github.com/projectdiscovery/nuclei/v3, github.com/projectdiscovery/nuclei and github.com/projectdiscovery/nuclei/v2.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/projectdiscovery/nuclei/v3` | Go | From 3.0.0 | 3.10.0 |
| `github.com/projectdiscovery/nuclei/v3` | Go | From 3.0.0 | 3.10.0 |
| `github.com/projectdiscovery/nuclei/v3` | Go | From 3.0.0 | 3.10.0 |
| `github.com/projectdiscovery/nuclei` | Go | All versions | None |
| `github.com/projectdiscovery/nuclei/v2` | Go | All versions | None |

## How do I fix CVE-2026-76803?

Upgrade github.com/projectdiscovery/nuclei/v3 to 3.10.0 or later.

## Is CVE-2026-76803 being exploited?

There is no known exploitation of CVE-2026-76803 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-76803 and fix it if it is affected.

What it is: CVE-2026-76803 is a medium-severity path traversal vulnerability in projectdiscovery nuclei, published on 22 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-76803 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/projectdiscovery/nuclei/v3 (Go): affected from 3.0.0; fixed in 3.10.0
- github.com/projectdiscovery/nuclei/v3 (Go): affected from 3.0.0; fixed in 3.10.0
- github.com/projectdiscovery/nuclei/v3 (Go): affected from 3.0.0; fixed in 3.10.0
- github.com/projectdiscovery/nuclei (Go): affected all versions; no fix listed
- github.com/projectdiscovery/nuclei/v2 (Go): affected all versions; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-76803/ (Markdown: https://insights.sbomify.com/CVE-2026-76803/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-76803
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-76803
- OSV: https://osv.dev/vulnerability/CVE-2026-76803

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-76803/
Summaries are generated and may contain mistakes; the official description above is the record.