CVE-2025-4144 describes a critical vulnerability in the OAuth implementation within Cloudflare's workers-oauth-provider, part of the MCP framework. An attacker can bypass the Proof Key for Code Exchange (PKCE) protection, which is a crucial defense-in-depth mechanism against certain OAuth attacks and a requirement in OAuth 2.1. This vulnerability carries a CVSS score of 9.8 (Critical) due to its network-based attack vector, low complexity, and high impact on confidentiality, integrity, and availability. Currently, there is no evidence of active exploitation, public exploit code, or significant community discussion surrounding this CVE.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
0.0.5CPE matchmatch criteria | cpe:2.3:a:cloudflare:workers-oauth-provider:0.0.5:*:*:*:*:*:*:* |
CVSS version used by this source: 4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Amber
The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 GitHub mentions.
No media coverage found for this CVE.
The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.