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CVE PROGRAM SOURCE RECORD7.5 High

CVE-2026-62864

Ring's nested-params middleware has inefficient regular expression complexity

Description

Ring is a Clojure web applications library inspired by Python's WSGI and Ruby's Rack. Prior to 1.15.5, `wrap-nested-params` in the `ring.middleware.nested-params` namespace uses a backtracking regular expression to match parameter names from URL query strings and HTTP request bodies. An attacker can craft a parameter name that drives quadratic O(n^2) matching work, causing regular-expression denial of service in applications using the middleware. `Ring-Defaults` users are also exposed because nested-params is enabled by default. Applications omitting the middleware do not expose this parsing path. This issue is fixed in version 1.15.5.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

ring-clojure ring

  • < 1.15.5affected

References