Description
runc is a CLI tool for spawning and running containers according to the OCI specification. In versions prior to 1.3.6, 1.4.0-rc.1, 1.4.0-rc.12, 1.5.0-rc.1, and 1.5.0-rc.1, when setting up the container rootfs, setupPtmx and setupDevSymlinks call os.Remove and os.Symlink with a filepath.Join string which allow an image with /dev as a symlink to trick runc into deleting files called ptmx on the host or creating a hardcoded set of symlinks with specific names and targets in an arbitrary pre-existing host directory. This issue is not exploitable under Docker, because Docker creates a top-level read-only layer that masks any malicious /dev symlink present in the container image — unlike some other Linux container tooling, whose higher-level runtimes built on runc remain exposed to exploitation via a malicious image. This issue has been fixed in versions 1.3.6, 1.4.3 and 1.5.0.
Published: 2026-07-01
Score: 3.3 Low
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-xjvp-4fhw-gc47 runc: Malicious image with /dev symlink can trigger limited host filesystem integrity violations
History

Wed, 01 Jul 2026 01:30:00 +0000

Type Values Removed Values Added
Description runc is a CLI tool for spawning and running containers according to the OCI specification. In versions prior to 1.3.6, 1.4.0-rc.1, 1.4.0-rc.12, 1.5.0-rc.1, and 1.5.0-rc.1, when setting up the container rootfs, setupPtmx and setupDevSymlinks call os.Remove and os.Symlink with a filepath.Join string which allow an image with /dev as a symlink to trick runc into deleting files called ptmx on the host or creating a hardcoded set of symlinks with specific names and targets in an arbitrary pre-existing host directory. This issue is not exploitable under Docker, because Docker creates a top-level read-only layer that masks any malicious /dev symlink present in the container image — unlike some other Linux container tooling, whose higher-level runtimes built on runc remain exposed to exploitation via a malicious image. This issue has been fixed in versions 1.3.6, 1.4.3 and 1.5.0.
Title runc: Malicious image with /dev symlink can trigger limited host filesystem integrity violations
Weaknesses CWE-61
References
Metrics cvssV3_1

{'score': 3.3, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N'}

Subscriptions

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-07-01T00:02:08.639Z

Reserved: 2026-04-21T14:15:21.958Z

Link: CVE-2026-41579

cve-icon Vulnrichment

No data.

cve-icon NVD

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cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

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Weaknesses