CVE-2025-31133: runc — Fix

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.

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CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

Weakness Type (CWE)

CWE-61 CWE-61

CWE-363 CWE-363

Affected Products

Vendor	Product	Versions
linuxfoundation	runc	< 1.2.8
linuxfoundation	runc	1.3.0 — 1.3.3
linuxfoundation	runc	All
linuxfoundation	runc	All

References

Advisories & Patches

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

Frequently Asked Questions

What is CVE-2025-31133? +

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. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2025-31133? +

CVE-2025-31133 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-31133? +

CVE-2025-31133 affects products from linuxfoundation, specifically: runc. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-31133? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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