Security Resilience

CVE-2026-56857

Published
08 October 2026
Modified
09 October 2026
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0049 41th percentile
Risk Priority 71 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-56857 is a critical-severity Insecure Operation on Windows Junction / Mount Point (CWE-1386) vulnerability in Go (inferred from references). Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Steganography (T1001.002); ranked at the 41th percentile by exploit likelihood (below the median); 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.

EU & UK References

Vulnerability Data

On Windows, when the target of Root.Mkdir or Root.MkdirAll is a junction pointing to an empty location, the operation can create a directory at the junction target even when that target is located outside the root. This only applies to…

more

operations where the last path component is a junction (path/to/junction, but not path/junction/target).

CWE(s)
CWE-1386

Related Threats

MITRE ATT&CK Enterprise Techniques

T1001.002 Steganography Command And Control
Adversaries may use steganographic techniques to hide command and control traffic to make detection efforts more difficult.
attack.mitre.org →
T1003.001 LSASS Memory Credential Access
Adversaries may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS).
attack.mitre.org →
T1003.008 /etc/passwd and /etc/shadow Credential Access
Adversaries may attempt to dump the contents of <code>/etc/passwd</code> and <code>/etc/shadow</code> to enable offline password cracking.
attack.mitre.org →
T1006 Direct Volume Access Stealth
Adversaries may directly access a volume to bypass file access controls and file system monitoring.
attack.mitre.org →
T1007 System Service Discovery Discovery
Adversaries may try to gather information about registered local system services.
attack.mitre.org →
T1010 Application Window Discovery Discovery
Adversaries may attempt to get a listing of open application windows.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-32470Shared CWE-1386
CVE-2024-36340Shared CWE-1386
CVE-2024-7400Shared CWE-1386
CVE-2025-58074Shared CWE-1386
CVE-2023-23698Shared CWE-1386
CVE-2023-40623Shared CWE-1386
CVE-2023-28071Shared CWE-1386
CVE-2023-5834Shared CWE-1386
CVE-2023-23697Shared CWE-1386
CVE-2023-32474Shared CWE-1386

Affected Assets

Go
—
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V5.3.3

Mitigating Controls (NIST 800-53 r5) AI

AC-3 Access Enforcement partial match

Enforcing authorizations on file/directory opens structurally blocks access via junctions that escape the intended scope.

AC-4 Information Flow Enforcement partial match

Information-flow rules that validate the final target of a name prevent unintended data access through mount points or junctions.

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 partial match
blocks

Secure SDLC practices directly prevent improper junction/mount-point handling during design and coding.

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.

A.5.35 Independent review of information security partial match
removes
A.7.7 Clear desk and clear screen partial match
removes
A.8.25 Secure development life cycle partial match
blocks

Secure development lifecycle can mandate junction/mount-point validation during design and coding.

A.8.26 Application security requirements partial match
blocks

Application security requirements can explicitly require protection against Windows reparse-point attacks.

A.8.27 Secure system architecture and engineering principles partial match
blocks

A.8.27 mandates security-by-design, defence-in-depth, least-privilege, distrust-external-input and hardening principles plus design reviews that can catch and block insecure junction/mount-point handling in the architecture and code, but leaves a bounded remainder (e.g. third-party libraries, runtime config, or post-deployment changes) where the flaw can still be introduced and exploited.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly address safe file/directory handling to prevent insecure junction operations.

References