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


- **Severity:** High 7.5 (`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`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 28 Oct 2026
- **Updated:** 29 Oct 2026
- **Also known as:** GHSA-wc9c-hfh3-phxx

## What is CVE-2026-47235?

CVE-2026-47235 is a high-severity vulnerability in simulationcraft simc, published on 28 Oct 2026. 

### Official 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.

Weakness: CWE-787 (Out-of-bounds Write), CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2026-47235?


## How do I fix CVE-2026-47235?

No fix has been published for CVE-2026-47235 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-47235 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-47235 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-47235 and fix it if it is affected.

What it is: CVE-2026-47235 is a high-severity vulnerability in simulationcraft simc, published on 28 Oct 2026. 
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-47235 exists.

Affected product: simulationcraft simc. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-47235/ (Markdown: https://insights.sbomify.com/CVE-2026-47235/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-47235
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-47235
- OSV: https://osv.dev/vulnerability/CVE-2026-47235

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-47235/
Summaries are generated and may contain mistakes; the official description above is the record.