# CVE-2025-31133

## Summary

- **CVE ID:** CVE-2025-31133
- **Severity:** HIGH
- **CVSS Score:** 7.3 (CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H)
- **CWE:** CWE-61, CWE-363
- **Published:** Nov 6, 2025
- **Last Modified:** Mar 12, 2026

## Description

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 Products

- opencontainers — runc (< 1.2.8)
- opencontainers — runc (>= 1.3.0-rc.1, < 1.3.3)
- opencontainers — runc (>= 1.4.0-rc.1, <= 1.4.0-rc.3)

## References

- [CNA](https://github.com/opencontainers/runc/security/advisories/GHSA-9493-h29p-rfm2)
- [CNA](https://github.com/opencontainers/runc/commit/1a30a8f3d921acbbb6a4bb7e99da2c05f8d48522)
- [CNA](https://github.com/opencontainers/runc/commit/5d7b2424072449872d1cd0c937f2ca25f418eb66)
- [CNA](https://github.com/opencontainers/runc/commit/8476df83b534a2522b878c0507b3491def48db9f)
- [CNA](https://github.com/opencontainers/runc/commit/db19bbed5348847da433faa9d69e9f90192bfa64)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.84%
- **EPSS Percentile:** 55.6

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._