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.

Severity (CVSS)

Base score3.3
SeverityLow
VersionCVSS 3.1
VectorCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
Provided byCNA

Weaknesses

  • CWE-61 — CWE-61: UNIX Symbolic Link (Symlink) Following

Affected products

VendorProductVersions
opencontainersrunc< 1.3.6; >= 1.4.0-rc.1, < 1.4.3; >= 1.5.0-rc.1, < 1.5.0-rc.3

References

Authoritative sources

This page is a snapshot. For the latest enrichment and updates, view the record on CVE.org or the NVD.

Generated from the official CVE List on 01 Jul 2026 07:05 UTC.