# CVE-2026-47766: crun follows rootfs /dev symlink while creating default devices

> An attacker with a malicious OCI bundle can escape the container rootfs to create or overwrite device nodes and symlinks on the host filesystem.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 14 Aug 2026
- **Updated:** 14 Aug 2026
- **Also known as:** AZL-95985, BELL-CVE-2026-47766, DEBIAN-CVE-2026-47766, GHSA-7vwr-4279-7gq5, RHSA-2026:54855, SUSE-SU-2026:22247-1, SUSE-SU-2026:22395-1, UBUNTU-CVE-2026-47766, openSUSE-SU-2026:11030-1

## What is CVE-2026-47766?

CVE-2026-47766 is a medium-severity path traversal vulnerability in containers crun, published on 14 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

crun is an open source OCI Container Runtime fully written in C. Prior to version 1.28, crun's default device setup opens the container rootfs `/dev` directory without `O_NOFOLLOW`. If an OCI bundle contains `rootfs/dev` as a symlink and the bundle configuration does not mount `/dev`, crun follows that symlink and creates the default device nodes and stdio symlinks at the symlink target outside the container rootfs. In a local rootful crun replay, this created fixed device nodes and symlinks outside the rootfs before crun returned failure. A pre-existing file named `ptmx` in the target directory was also replaced by crun's forced `ptmx -> pts/ptmx` symlink. Version 1.28 fixes the issue.

Weakness: CWE-61 (UNIX Symbolic Link (Symlink) Following)

## Which versions are affected by CVE-2026-47766?


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `crun` | Red Hat:hummingbird:1 | All versions | 0:1.28-2.hum1 |
| `crun-krun` | Red Hat:hummingbird:1 | All versions | 0:1.28-2.hum1 |
| `crun-wasm` | Red Hat:hummingbird:1 | All versions | 0:1.28-2.hum1 |
| `crun` | SUSE:Linux Micro 6.0 | All versions | 1.14-3.1 |
| `crun` | SUSE:Linux Micro 6.1 | All versions | 1.15-slfo.1.1_2.1 |
| `crun` | openSUSE:Tumbleweed | All versions | 1.28-1.1 |

## How do I fix CVE-2026-47766?

Upgrade to a fixed version.

## Is CVE-2026-47766 being exploited?

There is no known exploitation of CVE-2026-47766 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-47766 and fix it if it is affected.

What it is: CVE-2026-47766 is a medium-severity path traversal vulnerability in containers crun, published on 14 Aug 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-2026-47766 in the wild and no public exploit code.

Affected product: containers crun. 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-2026-47766/ (Markdown: https://insights.sbomify.com/CVE-2026-47766/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-47766
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-47766
- OSV: https://osv.dev/vulnerability/CVE-2026-47766

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-47766/
Summaries are generated and may contain mistakes; the official description above is the record.