CVE-2026-71315: Nuxt route rules silently dropped for mixed-case paths, bypassing appMiddleware auth gates (incomplete fix for CVE-2026-53721)

Severity: high (CVSS 8.2 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: 2026-08-05 · updated 2026-09-08
Weakness: CWE-178

Description

Nuxt is an open-source web development framework for Vue.js. From 3.21.7 until 3.21.10 and 4.5.1, mixed-case routeRules keys can fail to match case-folded lookups when router.options.sensitive is false and drop appMiddleware authorization gates. This is caused by an incomplete fix for CVE-2026-53721. This issue is fixed in 3.21.10 and 4.5.1.

Affected products

nuxt: from 4.4.7, < 4.5.1; from 3.21.7, < 3.21.10

References

https://github.com/nuxt/nuxt/commit/619963309e082190bac4a26b05f2dd155b039b81
https://github.com/nuxt/nuxt/commit/ad624a75ad2d215f43633f6b40be346a7194d34d
https://github.com/nuxt/nuxt/releases/tag/v3.21.10
https://github.com/nuxt/nuxt/releases/tag/v4.5.1
https://github.com/nuxt/nuxt/security/advisories/GHSA-hxvh-4h3w-prp9

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