Disclosure summary
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.
Source-reported weakness categories
CWE-61, CWE-363
Source-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
NIST National Vulnerability Database · NVD-CVE-2025-52881
Open original source · Updated Oct 07, 2026
Only CPE matches marked vulnerable=true are indexed. AND/OR platform conditions must be checked in the original NVD record.
| Vendor | Product / association | Version / bounds |
|---|---|---|
| linuxfoundation | runc | * {"versionStartIncluding":"1.3.0","versionEndExcluding":"1.3.3"} |
| linuxfoundation | runc | 1.4.0 |
| linuxfoundation | runc | 1.4.0 |
Original records & references
- NIST NVD record
- CVE Program record
- github.com — Patch
- github.com — Patch
- github.com — Patch
- github.com — Patch
- github.com — Patch
- github.com — Patch
- github.com — Patch
- github.com — Patch
- github.com — Patch
- github.com — Patch
- github.com — Patch
- github.com — Patch
- github.com — Patch
- github.com — Patch
- github.com — Patch
- github.com — Patch, Third Party Advisory
- github.com — Exploit, Mitigation, Patch, Third Party Advisory
- github.com — Patch, Third Party Advisory
PUBLISHED 2025-11-06T16:15:42-05:00
MODIFIED 2026-10-07T17:10:00-04:00
INGESTED 2026-10-08T12:35:14-04:00