CVE-2026-100409CWE-177CWE-180

CVE-2026-100409

High · published October 15, 2026

CVSS v3.1
7.5
EPSS
0%
Percentile
22.1
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.00305 · 22.1th percentile
Weaknesses
CWE-177 · Improper Handling of URL Encoding (Hex Encoding); CWE-180 · Incorrect Behavior Order: Validate Before Canonicalize
Published
2026-10-15T21:17Z
References (5)
EPSS history
Timeline
  • 17 OCT 03:27Z
    EPSS moved — → 0%
    epss
  • 15 OCT 16:57Z
    OpenNext Cloudflare: Cache interception can bypass middleware protection for encoded paths
    cvelistv5
  • 15 OCT 16:57Z
    OpenNext Cloudflare: Cache interception can bypass middleware protection for encoded paths
    cvelistv5