🛡️ CVE-2026-54281 — platform-fastify

🟠 CVSS 8.0 — High ✅ No Known Exploit CWE-863 NVD
8.0
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Nest: Middleware Bypass on Fastify via Trailing Slash

Impact

An authentication bypass vulnerability exists in @nestjs/platform-fastify (confirmed on version 11.1.24, the latest available release at time of report). When middleware is registered through NestJS's MiddlewareConsumer.forRoutes() API on the Fastify adapter, an unauthenticated client can bypass the Nest middleware registered for that route by simply appending a trailing slash (/) to the request URL.

This bypass works on the default Fastify adapter configuration — no special router options need to be enabled. Applications using the standard CRUD route shape (GET /resource and GET /resource/:id) are affected when they protect those routes with MiddlewareConsumer.forRoutes() middleware.

Patches

Fixed in @nestjs/platform-fastify@11.1.24

References

Kudos goes to @a-tt-om

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. Rated impact: confidentiality high, integrity high, availability low.

Weakness class

CVE-2026-54281 is classified as CWE-863: Incorrect Authorization. An authorisation check runs but reaches the wrong conclusion, permitting actions it should refuse.

Affected software

CVE-2026-54281 is recorded against 2 packages.

  • @nestjs/platform-fastify
  • unknown

Timeline and source

Published on 15 June 2026 and last revised on 18 July 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

github.com (Web)
nvd.nist.gov (Advisory)
github.com (Package)

Details

Severity HIGH
CVSS Score 8.0
CVSS Vector CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N
CWE CWE-863
Public Exploit ✅ No
Source NVD
Published 2026-06-15
Updated 2026-08-20
Modified 2026-07-18
Fix URL N/A

Affected Packages

Software From version Fixed in
@nestjs/platform-fastify — —
unknown — —

Similar Threats

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