High 7.3Published Nov 6, 2025

CVE-2025-31133runc container escape via "masked path" abuse due to mount race conditions

Updated under an hour ago (Oct 27, 2026, 9:23 PM ET)

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It affects opencontainers runc and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for opencontainers runc

Exploited in the last 30 days

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.

CVSS: 7.3 HIGH (v4.0, CNA)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
Weakness (CWE): CWE-61, CWE-363
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Nov 6, 2025
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

opencontainers runc opencontainers:runc (from the name)	before 1.2.8; from 1.3.0-rc.1, < 1.3.3; from 1.4.0-rc.1, <= 1.4.0-rc.3	CNA record
linuxfoundation runc linuxfoundation:runc	before 1.2.8; from 1.3.0 before 1.3.3; 1.4.0; 1.4.0	NVD

References

References

https://github.com/opencontainers/runc/security/advisories/GHSA-9493-h29p-rfm2	x-refsource-confirm, mitigation, patch, third-party-advisory
https://github.com/opencontainers/runc/commit/1a30a8f3d921acbbb6a4bb7e99da2c05f8d48522	x-refsource-misc, patch
https://github.com/opencontainers/runc/commit/5d7b2424072449872d1cd0c937f2ca25f418eb66	x-refsource-misc, patch
https://github.com/opencontainers/runc/commit/8476df83b534a2522b878c0507b3491def48db9f	x-refsource-misc, patch
https://github.com/opencontainers/runc/commit/db19bbed5348847da433faa9d69e9f90192bfa64	x-refsource-misc, patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.