Vulnerability in Linuxfoundation Runc
CVE-2025-52881
runc is a CLI tool for spawning and running containers according to the OCI specification. In versions 1.2.7, 1.3.2 and 1.4.0-rc.2, an attacker can trick runc into misdirecting writes to /proc to other procfs files through the use of a racing container with shared mounts (we have also verified this attack is possible to exploit using a standard Dockerfile with docker buildx build as that also permits triggering parallel execution of containers with custom shared mounts configured). This redirect could be through symbolic links in a tmpfs or theoretically other methods such as regular bind-mounts. While similar, the mitigation applied for the related CVE, CVE-2019-19921, was fairly limited and effectively only caused runc to verify that when LSM labels are written they are actually procfs files. This issue is fixed in versions 1.2.8, 1.3.3, and 1.4.0-rc.3.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.006 (46.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 46th percentile — 46.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: +0.000
Affected products
- Linuxfoundation Runc — versions 1.4.0
- Opencontainers Runc — versions <= 1.2.7, < 1.2.8, <= 1.3.2, < 1.3.3, <= 1.4.0-rc.2, < 1.4.0-rc.3
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/opencontainers/runc/security/advisories/GHSA-cgrx-mc8f-2prm (Exploit, Patch, Third Party Advisory, Mitigation)
- github.com/opencontainers/runc/security/advisories/GHSA-qw9x-cqr3-wc7r (Patch, Third Party Advisory)
- github.com/opencontainers/runc/security/advisories/GHSA-9493-h29p-rfm2 (Patch, Third Party Advisory)
- github.com/opencontainers/runc/commit/ff94f9991bd32076c871ef0ad8bc1b763458e480 (Patch)
- github.com/opencontainers/runc/commit/ff6fe1324663538167eca8b3d3eec61e1bd4fa51 (Patch)
- github.com/opencontainers/runc/commit/ed6b1693b8b3ae7eb0250a7e76fc888cdacf98c1 (Patch)
- github.com/opencontainers/runc/commit/db19bbed5348847da433faa9d69e9f90192bfa64 (Patch)
- github.com/opencontainers/runc/commit/d61fd29d854b416feaaf128bf650325cd2182165 (Patch)
- github.com/opencontainers/runc/commit/d40b3439a9614a86e87b81a94c6811ec6fa2d7d2 (Patch)
- github.com/opencontainers/runc/commit/b3dd1bc562ed9996d1a0f249e056c16624046d28 (Patch)
Frequently asked questions
- What is CVE-2025-52881?
- CVE-2025-52881 is a high-severity vulnerability in Linuxfoundation Runc, classified under UNIX Symbolic Link (Symlink) Following. CVSS score: 7.5/10. Published 2025-11-06.
- How severe is CVE-2025-52881?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2025-52881 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.