# CVE-2026-110451: Security feature bypass in Nix

> Attackers can escape the Seatbelt sandbox on macOS due to a mishandled size threshold, bypassing security restrictions in Nix and Lix.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N`)
- **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:** 14 Oct 2026
- **Updated:** 14 Oct 2026
- **Also known as:** GHSA-5h53-jg3j-22gg, UBUNTU-CVE-2026-110451

## What is CVE-2026-110451?

CVE-2026-110451 is a medium-severity vulnerability in NixOS Nix, published on 14 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Nix before 2.35.3 and Lix before 2.95.4 on macOS allow a Seatbelt sandbox escape (for an unconfined build) because a certain size threshold is mishandled.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2026-110451?


## How do I fix CVE-2026-110451?

No fix has been published for CVE-2026-110451 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-110451 being exploited?

There is no known exploitation of CVE-2026-110451 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-110451 and fix it if it is affected.

What it is: CVE-2026-110451 is a medium-severity vulnerability in NixOS Nix, published on 14 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-110451 in the wild and no public exploit code.

Affected product: NixOS Nix. 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-2026-110451/ (Markdown: https://insights.sbomify.com/CVE-2026-110451/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-110451
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-110451
- OSV: https://osv.dev/vulnerability/CVE-2026-110451

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-110451/
Summaries are generated and may contain mistakes; the official description above is the record.