---
id: CVE-2025-31133
title: >-
  runc is a CLI tool for spawning and running containers according to the OCI
  specification
summary: >-
  runc is a CLI tool for spawning and running containers according to the OCI
  specification. In versions 1.2.7 and below, 1.3.0-rc.1 through 1.3.1,
  1.4.0-rc.1 and 1.4.0-rc.2 files, runc would not perform sufficient
  verification that the so…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H'
cwe:
  - CWE-61
  - CWE-363
vendor: linuxfoundation
product: runc
affected:
  - runc < 1.2.8
  - 'runc >= 1.3.0, < 1.3.3'
  - runc = 1.4.0
patched:
  - runc 1.3.3
published: '2025-11-06'
updated: '2026-10-07'
sourceUpdated: '2026-10-07T21:10:00.200'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-31133'
references:
  - url: >-
      https://github.com/opencontainers/runc/commit/1a30a8f3d921acbbb6a4bb7e99da2c05f8d48522
    label: security-advisories@github.com
  - url: >-
      https://github.com/opencontainers/runc/commit/5d7b2424072449872d1cd0c937f2ca25f418eb66
    label: security-advisories@github.com
  - url: >-
      https://github.com/opencontainers/runc/commit/8476df83b534a2522b878c0507b3491def48db9f
    label: security-advisories@github.com
  - url: >-
      https://github.com/opencontainers/runc/commit/db19bbed5348847da433faa9d69e9f90192bfa64
    label: security-advisories@github.com
  - url: >-
      https://github.com/opencontainers/runc/security/advisories/GHSA-9493-h29p-rfm2
    label: security-advisories@github.com
tags:
  - nvd
  - exploit-available
epss: 0.00844
epssPercentile: 0.56669
exploits:
  github: 3
  githubRepos:
    - 'https://github.com/skynet-f-nvidia/CVE-2025-31133'
    - 'https://github.com/C-h4ck-0/Learn-about-cve-2025-31133-poc'
    - 'https://github.com/scherepiuk/container-escape-ebpf'
  checkedAt: '2026-10-07T21:54:50.411Z'
exploitAvailable: true
ingestedAt: '2026-10-07T21:54:14.965Z'
---

## Overview

runc is a CLI tool for spawning and running containers according to the OCI specification. In versions 1.2.7 and below, 1.3.0-rc.1 through 1.3.1, 1.4.0-rc.1 and 1.4.0-rc.2 files, runc would not perform sufficient verification that the source of the bind-mount (i.e., the container's /dev/null) was actually a real /dev/null inode when using the container's /dev/null to mask. This exposes two methods of attack:  an arbitrary mount gadget, leading to host information disclosure, host denial of service, container escape, or a bypassing of maskedPaths. This issue is fixed in versions 1.2.8, 1.3.3 and 1.4.0-rc.3.

## Affected

- `runc < 1.2.8`
- `runc >= 1.3.0, < 1.3.3`
- `runc = 1.4.0`

## Remediation

Upgrade past the affected range:

- `runc 1.3.3`