CVE-2025-4144

CriticalCVSS 9.8/10Last modified Jun 17, 2026

Description

PKCE was implemented in the OAuth implementation in workers-oauth-provider that is part of MCP framework https://github.com/cloudflare/workers-mcp . However, it was found that an attacker could cause the check to be skipped.

Fixed in:

https://github.com/cloudflare/workers-oauth-provider/pull/27 https://github.com/cloudflare/workers-oauth-provider/pull/27

Impact:

PKCE is a defense-in-depth mechanism against certain kinds of attacks and was an optional extension in OAuth 2.0 which became required in the OAuth 2.1 draft. (Note that the MCP specification requires OAuth 2.1.). This bug completely bypasses PKCE protection.

Metrics

CVSS 3.1 9.8/10CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weakness enumeration

CWE-287

Affected software

No affected versions have been published.

Timeline

Published: May 1, 2025
Last modified: Jun 17, 2026
NVD status: Analyzed

Related CVEs from 2025

CVE-2025-414415.3Mailform Pro CGI prior to 4.3.4 generates error messages containing sensitive information, which may allow a remote unauthenticated attacker CVE-2025-414425.4A vulnerability exists in Advantech iView versions prior to 5.7.05 build 7057, which could allow a reflected cross-site scripting (XSS) att CVE-2025-414434.3Mattermost versions 10.5.x <= 10.5.12, 10.11.x <= 10.11.2 fail to properly validate guest user permissions when accessing channel informatio CVE-2025-414448.3Zohocorp ManageEngine ADAudit Plus versions 8510 and prior are vulnerable to authenticated SQL injection in the alerts module.CVE-2025-41459.8A vulnerability, which was classified as critical, has been found in Netgear EX6200 1.0.3.94. This issue affects the function sub_3D0BC. The CVE-2025-414508.2Improper Authentication vulnerability in Danfoss AKSM8xxA Series.This issue affects Danfoss AK-SM 8xxA Series prior to version 4.2 CVE-2025-414518.7Improper neutralization of alarm-to-mail configuration fields used in an OS shell Command ('Command Injection') in Danfoss AK-SM8xxA Series CVE-2025-414526.8Post-authenticated external control of system web interface configuration setting vulnerability in Danfoss AK-SM8xxA Series prior to 4.3.1, CVE-2025-414585.5Unencrypted storage in the database in Two App Studio Journey v5.5.9 for iOS allows local attackers to extract sensitive data via direct acc CVE-2025-414597.8Insufficient protection against brute-force and runtime manipulation in the local authentication component in Two App Studio Journey 5.5.6 o CVE-2025-41469.8A vulnerability, which was classified as critical, was found in Netgear EX6200 1.0.3.94. Affected is the function sub_41940. The manipulatio CVE-2025-41479.8A vulnerability has been found in Netgear EX6200 1.0.3.94 and classified as critical. Affected by this vulnerability is the function sub_47F