{"id":"CVE-2026-62864","title":"Ring's nested-params middleware has inefficient regular expression complexity","summary":"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 …","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvssSource":"cna","cwe":["CWE-1333"],"vendor":"ring-clojure","product":"ring","affected":["ring < 1.15.5"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-11-02T15:04:29.414692Z"},"published":"2026-10-30","updated":"2026-11-02","sourceUpdated":"2026-11-02T15:05:18.669Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-62864","references":[{"url":"https://github.com/ring-clojure/ring/security/advisories/GHSA-q2j3-fc6x-78jj","label":"https://github.com/ring-clojure/ring/security/advisories/GHSA-q2j3-fc6x-78jj"},{"url":"https://github.com/ring-clojure/ring/commit/18738cbb8ab7504da4a5c72c9eb5fdcbf142646e","label":"https://github.com/ring-clojure/ring/commit/18738cbb8ab7504da4a5c72c9eb5fdcbf142646e"},{"url":"https://github.com/ring-clojure/ring/tree/1.15.5","label":"https://github.com/ring-clojure/ring/tree/1.15.5"}],"tags":["cve.org"],"epss":0.00339,"epssPercentile":0.27483,"ingestedAt":"2026-11-05T19:30:42.689Z","slug":"CVE-2026-62864","body":"## Overview\n\nRing 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.\n\n## Affected\n\n- `ring < 1.15.5`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}