CVE-2026-62864
Dashboard / Vulnerabilities / CVE-2026-62864
Summary: Ring's nested-params middleware has inefficient regular expression complexity
Details: 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.
References: https://github.com/ring-clojure/ring/tree/1.15.5, https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/62xxx/CVE-2026-62864.json, https://github.com/ring-clojure/ring/security/advisories/GHSA-q2j3-fc6x-78jj, https://nvd.nist.gov/vuln/detail/CVE-2026-62864, https://github.com/ring-clojure/ring/commit/18738cbb8ab7504da4a5c72c9eb5fdcbf142646e
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