CVE-2024-21626
HighCVSS 8.6Exploitation Probability (EPSS)
Very high risk97th percentile - higher than 97% of all known CVEs
Summary
A vulnerability in runc 1.1.11 and earlier is caused by an internal file descriptor leak, allowing an attacker to set the working directory of a container process to the host filesystem namespace. This enables container escape and access to the host filesystem via runc exec or runc run. Additional attack variants allow overwriting host binaries, leading to complete container escape.
Risk Assessment
The organization faces the risk of full host compromise, where an attacker can access sensitive data, modify system files, or execute malicious code outside the container.
Recommendation
Immediately update runc to version 1.1.12 or later. Before updating, restrict trusted container images and monitor container activity for suspicious behavior.
Other vulnerabilities in runc
See all- CVE-2025-52565High
runc is a CLI tool for spawning and running containers according to the OCI specification. Versions 1.0.0-rc3 through 1.2.7, 1.3.0-rc.1 through 1.3.2, and 1.4.0-rc.1 through 1.4.0-rc.2, due to insufficient checks when bind-mounting `/dev/pts/$n` to `/dev/console` inside the container, an attacker can...
- CVE-2025-31133High
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, runc would not perform sufficient verification that the source of the bind-mount (i.e., the container's /dev/null) was actually...
- CVE-2024-45310Medium
runc 1.1.13 and earlier, as well as 1.2.0-rc2 and earlier, can be tricked into creating empty files or directories in arbitrary locations in the host filesystem by sharing a volume between two containers and exploiting certain operations.
- CVE-2026-41579Low
In runc prior to versions 1.3.6, 1.4.3, and 1.5.0, setupPtmx and setupDevSymlinks use filepath.Join with os.Remove and os.Symlink, allowing an image with /dev as a symlink to delete the ptmx file on the host or create symlinks in an arbitrary host directory. This is not exploitable under Docker, but other container tooling built on runc remains exposed.
Original NVD description (English source)
runc is a CLI tool for spawning and running containers on Linux according to the OCI specification. In runc 1.1.11 and earlier, due to an internal file descriptor leak, an attacker could cause a newly-spawned container process (from runc exec) to have a working directory in the host filesystem namespace, allowing for a container escape by giving access to the host filesystem ("attack 2"). The same attack could be used by a malicious image to allow a container process to gain access to the host filesystem through runc run ("attack 1"). Variants of attacks 1 and 2 could be also be used to overwrite semi-arbitrary host binaries, allowing for complete container escapes ("attack 3a" and "attack 3b"). runc 1.1.12 includes patches for this issue.