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.
INFO
Published Date :
Oct. 30, 2026, 9:17 p.m.
Last Modified :
Oct. 30, 2026, 9:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-62864
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update Ring web applications library to version 1.15.5.
- Review and update `ring-defaults` if used.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-62864.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-62864 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-62864
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-62864 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-62864 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Oct. 30, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-1333 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/62xxx/CVE-2026-62864.json">CVE-2026-62864</a> Added Reference https://github.com/ring-clojure/ring/commit/18738cbb8ab7504da4a5c72c9eb5fdcbf142646e Added Reference https://github.com/ring-clojure/ring/security/advisories/GHSA-q2j3-fc6x-78jj Added Reference https://github.com/ring-clojure/ring/tree/1.15.5