CVE-2026-100409

7.5High

Published 15 Oct 2026 · NVD status: Deferred · AI triage by gemini-3.8-flash

7.5High

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None
Impact: High impact on confidentiality
Weakness: CWE-177, CWE-180

Impact

Unauthenticated remote attackers can bypass authorization middleware and read cached responses for protected routes. They only need network access to send specially crafted, percent-encoded URLs.

Root cause

Inconsistent URL path decoding between middleware routing checks and the cache lookup allows mismatched paths to retrieve cached content.

Affected systems

OpenNext Cloudflare (package @opennextjs/cloudflare) 0.3.0 before 1.20.2 with enableCacheInterception enabled

CVSS v3.1 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Fix & remediation

Upgrade @opennextjs/cloudflare to version 1.20.2 or later. If patching immediately is not possible, disable enableCacheInterception in your configuration.

shell

$ npm install @opennextjs/cloudflare@^1.20.2

AI-suggested. Run it in staging first and check it against the vendor advisory. Why?

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NVD description

OpenNext Cloudflare is an open Next.js adapter for Cloudflare. From 0.3.0 until 1.20.2, applications that enable enableCacheInterception, rely on middleware for access control, and have a matching cached protected route process encoded pathnames inconsistently between middleware matching and cache lookup. An unauthenticated attacker can use a percent-encoded pathname that does not match authorization middleware but decodes to the cache key of a protected route, causing cached content to be returned without authorization. Malformed encodings can also be partially decoded, allowing cache lookup to continue with a pathname that middleware did not evaluate consistently. This issue is fixed in version 1.20.2.

References

Source: nvd.nist.gov/vuln/detail/CVE-2026-100409