CVE-2024-21626
runc container breakout through process.cwd trickery and leaked fds
- Published
- Jan 31, 2024
- Updated
- Sep 17, 2026
- Assigning CNA
- GitHub_M
- Evidence observed
- Aug 8, 2026
Primary CVSS
nvd · CVSS 3.1
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:HModerate · next 30 days
- Percentile
- 97.3%
- Model date
- Oct 17, 2026
EPSS is a statistical estimate, not a certainty or a measure of impact. Combine it with CVSS, KEV status, exposure and your environment.
Summary
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.
Sources
modules/exploits/linux/local/runc_cwd_priv_esc.rb
Metasploit Framework modulesDeclared conditions
- platform: Linux($.exploit_linux/local/runc_cwd_priv_esc.platform)
- verification: check_declared($.exploit_linux/local/runc_cwd_priv_esc.check)
Responsible use
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