CVE-2026-6410: @fastify/static vulnerable to path traversal in directory listing

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-04-16 · updated 2026-06-17
Weakness: CWE-22

Description

@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 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.

Affected products

https://github.com/fastify/fastify-static: from 8.0.0 before 9.1.1 — fixed in 9.1.1

How to fix

Upgrade to a fixed version: https://github.com/fastify/fastify-static 9.1.1. Check the vendor advisory for mitigations.

References

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