CVE-2025-31133 - CVE House
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Status published High CVE-2025-31133

runc container escape via "masked path" abuse due to mount race conditions

Vulnerability 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.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

References

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CVE-2024-45310
runc can be confused to create empty files/directories on the host
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CVE-2024-21626
runc container breakout through process.cwd trickery and leaked fds
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CVE-2023-28642
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Medium 6.1

Affected Vendor

opencontainers

View all reports →

Affected Software

runc
Vulnerable Versions:
< 1.2.8, >= 1.3.0-rc.1, < 1.3.3, >= 1.4.0-rc.1, <= 1.4.0-rc.3

Timeline

Official Publish: November 6th, 2025
Last Modified: November 6th, 2025
Added to House: July 22nd, 2026

CVSS Vectors

Weaknesses (CWE)

CWE-61 CWE-363

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.