Cyber Resilience

CVE-2026-27139

Path Traversal in Golang Go ≤ 1.25.8

Published
06 March 2026
Modified
21 April 2026
Patch / advisory
CVSS Score v3.1 2.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
EPSS Score 0.0020 10th percentile
Risk Priority 15 floored blend · peak EPSS

Summary

CVE-2026-27139 is a low-severity Path Traversal (CWE-22) vulnerability in Golang Go. Its CVSS base score is 2.5 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique File and Directory Discovery (T1083); ranked at the 10th 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 SI-10 (Information Input Validation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

On Unix platforms, when listing the contents of a directory using File.ReadDir or File.Readdir the returned FileInfo could reference a file outside of the Root in which the File was opened. The impact of this escape is limited to reading…

more

metadata provided by lstat from arbitrary locations on the filesystem without permitting reading or writing files outside the root.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1083 File and Directory Discovery Discovery
Adversaries may enumerate files and directories or may search in specific locations of a host or network share for certain information within a file system.
Why these techniques?

Path traversal in directory listing enables filesystem metadata enumeration outside intended root (T1083 File and Directory Discovery).

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2023-45283Same product: Golang Go
CVE-2025-65713Shared CWE-22
CVE-2025-64235Shared CWE-22
CVE-2026-42885Shared CWE-22
CVE-2026-28769Shared CWE-22
CVE-2024-45604Shared CWE-22
CVE-2025-62856Shared CWE-22
CVE-2025-61557Shared CWE-22
CVE-2025-62855Shared CWE-22
CVE-2026-33238Shared CWE-22

Affected Assets

golang
go
1.26.0 · ≤ 1.25.8

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-10 Information Input Validation
  • AC-3 Access Enforcement
  • AC-6 Least Privilege
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V5.3.2

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly validates untrusted path inputs to File.ReadDir/Readdir to block traversal that leaks lstat metadata outside the intended root.

prevent

Enforces that directory-listing operations may only return FileInfo entries that reside inside the opened root, preventing the observed escape.

prevent

Limits the calling process to the minimal set of directories it may open, reducing the filesystem surface reachable by the lstat-metadata leak.

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-02 partial match
prevents

Patching/maintenance can remediate known path-traversal flaws in deployed software (partial prevention of exploitability) but does nothing to stop the coding defect from being introduced in the first place.

PR.AA-05 none match
prevents

PR.AA-05 defines and reviews access policies but does not address code-level pathname neutralization, so neither direction prevents CWE-22.

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.

detects

Security testing in development catches path traversal via static/dynamic analysis.

prevents

Secure SDLC mandates input validation and path sanitization that directly prevent path traversal.

prevents

Application security requirements include rules for safe file handling and canonicalization.

prevents

Secure architecture principles require least-privilege file access and directory isolation.

prevents

Secure coding standards explicitly forbid unsafe path construction and mandate safe APIs.

mitigates

Information access restriction limits which files an application may read or write.

References