Cyber Resilience

CVE-2026-6410

Path Traversal in Fastify-Static 8.0.0 – 9.1.1

Published
16 April 2026
Modified
23 April 2026
Patch / advisory
CVSS Score v3.1 5.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS Score 0.0051 40th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-6410 is a medium-severity Path Traversal (CWE-22) vulnerability in Fastify Fastify-Static. Its CVSS base score is 5.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 40th 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

@fastify/static versions 8.0.0 through 9.1.0 allow path traversal when directory listing is enabled via the list option. The dirList.path() function resolves directories outside the configured static root using path.join() without a containment check. A remote unauthenticated attacker can obtain directory…

more

listings for arbitrary directories accessible to the Node.js process, disclosing directory and file names. File contents are not disclosed. Upgrade to @fastify/static 9.1.1 to fix this issue. As a workaround, disable directory listing by removing the list option from the plugin configuration.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
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 public-facing static file server directly enables remote directory/file name discovery (T1083) via exploitation of a web application (T1190).

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

CVEs Like This One

CVE-2025-67653Shared CWE-22
CVE-2026-33670Shared CWE-22
CVE-2025-14182Shared CWE-22
CVE-2025-50350Shared CWE-22
CVE-2026-52756Shared CWE-22
CVE-2025-5714Shared CWE-22
CVE-2026-34523Shared CWE-22
CVE-2025-67171Shared CWE-22
CVE-2023-49508Shared CWE-22
CVE-2024-50843Shared CWE-22

Affected Assets

fastify
fastify-static
8.0.0 — 9.1.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-10 Information Input Validation
  • AC-3 Access Enforcement
  • CM-7 Least Functionality
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

Validates path inputs to the dirList.path() function so that path.join() results cannot escape the configured static root.

prevent

Enforces an access-control policy that only permits directory listings inside the declared static root, blocking traversal requests before they succeed.

prevent

Disables the list option (directory-listing feature) entirely, removing the vulnerable code path from the deployed @fastify/static instance.

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