Cyber Resilience

CVE-2025-31133

Race Condition in Linuxfoundation Runc ≤ 1.2.8

Published
06 November 2025
Modified
03 December 2025
Patch / advisory
CVSS Score v4 7.3
Click a component to see what it means
Raw vectorCVSS: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
EPSS Score 0.0084 55th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2025-31133 is a high-severity UNIX Symbolic Link (Symlink) Following (CWE-61) vulnerability in Linuxfoundation Runc. Its CVSS base score is 7.3 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Path Interception (T1034); ranked in the top 45% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-4 (Information Flow Enforcement) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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.,…

more

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.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1034 Path Interception Persistence
**This technique has been deprecated.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-45310Same product: Linuxfoundation Runc
CVE-2025-52881Same product: Linuxfoundation Runc
CVE-2025-52565Same product: Linuxfoundation Runc
CVE-2026-41579Same product: Linuxfoundation Runc
CVE-2023-28642Same product: Linuxfoundation Runc
CVE-2023-25809Same product: Linuxfoundation Runc
CVE-2026-53489Same vendor: Linuxfoundation
CVE-2025-62161Shared CWE-363, CWE-61
CVE-2025-62596Shared CWE-363, CWE-61
CVE-2026-34446Same vendor: Linuxfoundation

Affected Assets

linuxfoundation
runc
1.4.0 · ≤ 1.2.8 · 1.3.0 — 1.3.3

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 2 hardening rules · 2 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V15.4.2
  • V5.2.5

Mitigating Controls (NIST 800-53 r5) AI

Access enforcement must resolve the actual target of any file reference and apply authorizations to it, directly stopping symlink traversal to unauthorized objects.

Information-flow enforcement on file operations must follow the resolved target rather than the link name, blocking unauthorized data movement via symlinks.

Least-privilege restrictions on the directories that may contain links or targets reduce the set of files an attacker can reach even if a symlink is followed.

SA-8 mandates security engineering principles that include atomic operations and safe file handling, preventing introduction of check-then-use race conditions.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly prevent introduction of symlink-following flaws in file-handling code.

ID.RA-01 partial match
prevents

Vulnerability identification can discover existing symlink issues but does not prevent or remediate them in code.

PR.AA-05 partial match
prevents

Least-privilege access policies can limit damage from symlink attacks but do not address the coding flaw itself.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing can detect symlink-following vulnerabilities before deployment, covering most of the weakness.

prevents

Secure development lifecycle practices can include TOCTOU-safe file handling, but do not guarantee elimination of link-following races.

prevents

Application security requirements can mandate atomic file operations, yet the control is broader than this specific race condition.

prevents

Secure-architecture principles require safe file-handling and canonicalization, directly addressing symlink attacks.

prevents

Secure-coding standards mandate explicit symlink checks and safe open patterns, fully mitigating CWE-61.

mitigates

Access-control rules can restrict which files a process may open, reducing symlink-following risk but not eliminating the underlying path-resolution flaw.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248577 OL 8 must enable kernel parameters to enforce Discretionary Access Control (DAC) on symlinks. prevents CWE-61

References