CVE-2026-15074

HIGH

@fastify/static vulnerable to route guard bypass via path traversal

Title source: cna
STIX 2.1

Description

@fastify/static up to and including version 10.1.0 fails to reject dot-dot path segments in request pathnames before the file-resolution stage. This is a bypass of the earlier fix for CVE-2026-6414, which only covered encoded forward slashes. Because the underlying send library normalizes dot segments before applying its own path-traversal guard, an unauthenticated attacker can bypass any route-scoped middleware and read files inside the static root that live under the guarded URL prefix. The bypass does not allow access outside the configured static root by itself, it defeats route-guard filtering only. The issue is patched in @fastify/static 10.1.1.

Scores

CVSS v3 7.5
EPSS 0.0045
EPSS Percentile 36.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-22
Status published
Products (4)
@fastify/static/@fastify/static < 10.1.1
@fastify/static/@fastify/static 10.1.1
fastify/fastify-static < 10.1.1
fastify/static 0 - 10.1.1npm
Published Jul 23, 2026
Tracked Since Jul 23, 2026