Vulnerability · Published Jul 1, 2026 · Assigned by GitHub_M

CVE-2026-41579runc: Malicious image with /dev symlink can trigger limited host filesystem integrity violations

Low 3.3

In plain English

A low-severity security flaw in runc from opencontainers. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)3.3Low
Exploit odds (30 days)0.2%top 91.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.24runc1.4.3-r0ALPINE-CVE-2026-41579
Debian:12runcno fix listedDEBIAN-CVE-2026-41579
Debian:13runcno fix listedDEBIAN-CVE-2026-41579
Debian:14runc1.3.6+ds1-1DEBIAN-CVE-2026-41579
Gogithub.com/opencontainers/runc1.3.6, 1.4.3, 1.5.0-rc.3GO-2026-5761
Gogithub.com/opencontainers/runc1.3.6GHSA-xjvp-4fhw-gc47
Gogithub.com/opencontainers/runc1.4.3GHSA-xjvp-4fhw-gc47
Gogithub.com/opencontainers/runc1.5.0-rc.3GHSA-xjvp-4fhw-gc47
Ubuntu:22.04:LTSruncno fix listedUBUNTU-CVE-2026-41579
Ubuntu:24.04:LTSruncno fix listedUBUNTU-CVE-2026-41579
Ubuntu:25.10runcno fix listedUBUNTU-CVE-2026-41579
Ubuntu:26.04:LTSruncno fix listedUBUNTU-CVE-2026-41579
Ubuntu:26.10runcno fix listedUBUNTU-CVE-2026-41579
Ubuntu:22.04:LTSrunc-appno fix listedUBUNTU-CVE-2026-41579
Ubuntu:24.04:LTSrunc-appno fix listedUBUNTU-CVE-2026-41579
Ubuntu:25.10runc-appno fix listedUBUNTU-CVE-2026-41579
Ubuntu:26.04:LTSrunc-appno fix listedUBUNTU-CVE-2026-41579
Ubuntu:26.10runc-appno fix listedUBUNTU-CVE-2026-41579
Ubuntu:25.10runc-stableno fix listedUBUNTU-CVE-2026-41579
Ubuntu:26.04:LTSrunc-stableno fix listedUBUNTU-CVE-2026-41579
Ubuntu:26.10runc-stableno fix listedUBUNTU-CVE-2026-41579

Affected products (as reported)

VendorProductVersions
opencontainers runc < 1.3.6>= 1.4.0-rc.1, < 1.4.3>= 1.5.0-rc.1, < 1.5.0-rc.3

Weakness: CWE-61 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

References