runc container escape via "masked path" abuse due to mount race conditions
Summary
| CVE | CVE-2025-31133 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2025-11-06 19:15:41 UTC |
| Updated | 2026-10-07 21:10:00 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v4.0 7.3 HIGH from [email protected]
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
Problem Types: CWE-61 | CWE-363 | CWE-61 CWE-61: UNIX Symbolic Link (Symlink) Following | CWE-363 CWE-363: Race Condition Enabling Link Following
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 7.3 | HIGH | 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/C... |
| 4.0 | CNA | DECLARED | 7.3 | HIGH | 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 |
| 3.1 | [email protected] | Primary | 7.8 | HIGH | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H |
CVSS v4.0 Breakdown
Attack Vector
LocalAttack Complexity
LowAttack Requirements
PresentPrivileges Required
LowUser Interaction
ActiveConfidentiality
HighIntegrity
HighAvailability
HighSub Conf.
HighSub Integrity
HighSub Availability
HighCVSS: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
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
HighPrivileges Required
LowUser Interaction
NoneScope
ChangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | Linuxfoundation | Runc | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Opencontainers | Runc | affected < 1.2.8 | Not specified |
| CNA | Opencontainers | Runc | affected >= 1.3.0-rc.1, < 1.3.3 | Not specified |
| CNA | Opencontainers | Runc | affected >= 1.4.0-rc.1, <= 1.4.0-rc.3 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/opencontainers/runc/commit/5d7b2424072449872d1cd0c937f2ca25f4... | [email protected] | github.com | Patch |
| github.com/opencontainers/runc/commit/1a30a8f3d921acbbb6a4bb7e99da2c05f8... | [email protected] | github.com | Patch |
| github.com/opencontainers/runc/commit/8476df83b534a2522b878c0507b3491def... | [email protected] | github.com | Patch |
| github.com/opencontainers/runc/security/advisories/GHSA-9493-h29p-rfm2 | [email protected] | github.com | Mitigation, Patch, Third Party Advisory |
| github.com/opencontainers/runc/commit/db19bbed5348847da433faa9d69e9f9019... | [email protected] | github.com | Patch |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.