{"affected":[{"product":"ring","source":"CNA: GitHub_M","vendor":"ring-clojure","versions":[{"status":"affected","version":"< 1.15.5"}]}],"cveId":"CVE-2026-62864","cwes":["CWE-1333"],"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.","epss":{"date":"2026-11-02","percentile":0.27344,"score":0.00339},"exploits":[],"kev":null,"metrics":[{"score":7.5,"severity":"high","source":"CNA: GitHub_M","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},{"score":7.5,"severity":"high","source":"NVD: security-advisories@github.com","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}],"modifiedAt":1793636262100,"publishedAt":1793392482963,"references":[{"source":"CNA: GitHub_M","tags":["x_refsource_CONFIRM"],"url":"https://github.com/ring-clojure/ring/security/advisories/GHSA-q2j3-fc6x-78jj"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/ring-clojure/ring/commit/18738cbb8ab7504da4a5c72c9eb5fdcbf142646e"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/ring-clojure/ring/tree/1.15.5"},{"source":"security-advisories@github.com","tags":[],"url":"https://github.com/ring-clojure/ring/commit/18738cbb8ab7504da4a5c72c9eb5fdcbf142646e"},{"source":"security-advisories@github.com","tags":[],"url":"https://github.com/ring-clojure/ring/security/advisories/GHSA-q2j3-fc6x-78jj"},{"source":"security-advisories@github.com","tags":[],"url":"https://github.com/ring-clojure/ring/tree/1.15.5"}],"remediation":[],"revision":"1129a5220a372498c403e97786324ed1f18208db6b978b184102bd80868ad31d","sources":[{"modifiedAt":1793631918669,"name":"CNA: GitHub_M","retrievedAt":1793635763777,"url":"https://www.cve.org/CVERecord?id=CVE-2026-62864"},{"modifiedAt":1793636262100,"name":"NVD","retrievedAt":1793643476168,"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-62864"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1793635807440,"url":"https://api.first.org/data/v1/epss?cve=CVE-2026-62864"}],"ssvc":{"assessedAt":1793631869414,"automatable":"yes","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"partial"},"status":"published","title":"Ring's nested-params middleware has inefficient regular expression complexity","updatedAt":1793643476168}