CVE-2025-31133: CVE-2025-31133: runc is a CLI tool for spawning and running containers according to the OCI specification.…
linuxfoundation · runc · NVD published 2025-11-07 · posted 2025-11-12 · last modified 2026-10-08
What it is
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 files, runc would not perform sufficient verification that the source of the bind-mount (i.e., the container's /dev/null) was actually a real /dev/null inode when using the container's /dev/null to mask. This exposes two methods of attack: an arbitrary mount gadget, leading to host information disclosure, host denial of service, container escape, or a bypassing of maskedPaths. This issue is fixed in versions 1.2.8, 1.3.3 and 1.4.0-rc.3.
| Weakness | CWE-61CWE-363 |
|---|---|
| CVSS vector | CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X (source: [email protected]) |
| ATT&CK tactics | Impact |
Exploitation evidence
First exploit evidence seen: 2025-11-12 (earliest date across the sources below).
Exploited in the wild
No source on this site lists in-the-wild exploitation yet (CISA KEV, VulnCheck KEV).
Public exploit code
GitHub proof-of-concept repositories
3 public repositories from 3 accounts, first seen 2025-11-12. Most starred: skynet-f-nvidia/CVE-2025-31133 (2 stars), view repository.
Verify before running: public PoCs can be malicious. Read the code and only run it in an isolated lab. A PoC means exploit code is public, not that this CVE is exploited in the wild.
Sources: nomi-sec/PoC-in-GitHub.
How to fix it
Fixed versions
- linuxfoundation runc: upgrade to 1.2.8 or later
- linuxfoundation runc: upgrade to 1.3.3 or later (affected from 1.3.0)
Derived from the NVD CPE configuration (versionEndExcluding / versionEndIncluding). Always confirm with the vendor advisory.
Vendor advisories and patches
- https://github.com/opencontainers/runc/commit/1a30a8f3d921acbbb6a4bb7e99da2c05f8d48522 (Patch)
- https://github.com/opencontainers/runc/commit/5d7b2424072449872d1cd0c937f2ca25f418eb66 (Patch)
- https://github.com/opencontainers/runc/commit/8476df83b534a2522b878c0507b3491def48db9f (Patch)
- https://github.com/opencontainers/runc/commit/db19bbed5348847da433faa9d69e9f90192bfa64 (Patch)
- https://github.com/opencontainers/runc/security/advisories/GHSA-9493-h29p-rfm2 (Mitigation, Patch, Third Party Advisory)
MITRE ATT&CK mitigations for this chain
- M1037 Filter Network Traffic (for T1499) : Leverage services provided by Content Delivery Networks (CDN) or providers specializing in DoS mitigations to filter traffic upstream from services. Filter boundary traffic by blocking source addresses sourcing the attack, blocking ports that are being targeted, or blocking protocols being used for transport. To defend
Detection Generic guidance
- Impact: Monitor service availability, unexpected encryption activity and mass file changes.
Response checklist Generic guidance
- Inventory: find every instance of the affected product and version (include internet-facing and forgotten ones).
- Patch or mitigate per the vendor advisory; if you cannot patch, remove internet exposure or apply the vendor workaround.
- Assume compromise if the system was exposed before patching: hunt for the indicators in the advisory and review logs back to the disclosure date.
- Rotate credentials and secrets stored on or used by the affected system if compromise cannot be ruled out.