# CVE-2026-8261: Squirrel sqobject.cpp Load heap-based overflow

> A heap-based buffer overflow in the Squirrel library allows local attackers to execute arbitrary code or cause denial of service via crafted input.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 May 2026
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2026-8261, GHSA-r4m3-922m-v5vr, UBUNTU-CVE-2026-8261

## What is CVE-2026-8261?

CVE-2026-8261 is a medium-severity memory corruption vulnerability in Squirrel, published on 11 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability was determined in Squirrel up to 3.2. This affects the function SQFunctionProto::Load of the file squirrel/sqobject.cpp. This manipulation causes heap-based buffer overflow. The attack is restricted to local execution. The exploit has been publicly disclosed and may be utilized. The project was informed of the problem early through an issue report but has not responded yet.

Weakness: CWE-122 (Heap-based Buffer Overflow), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2026-8261?


## How do I fix CVE-2026-8261?

No fix has been published for CVE-2026-8261 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-8261 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-8261 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-8261 and fix it if it is affected.

What it is: CVE-2026-8261 is a medium-severity memory corruption vulnerability in Squirrel, published on 11 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-8261 exists.

Affected product: Squirrel. 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-2026-8261/ (Markdown: https://insights.sbomify.com/CVE-2026-8261/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-8261
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-8261
- OSV: https://osv.dev/vulnerability/CVE-2026-8261

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-8261/
Summaries are generated and may contain mistakes; the official description above is the record.