PT-2025-18345 · Unknown · Workers-Oauth-Provider

Published 2025-05-01 · Updated 2025-05-01 · CVE-2025-4144

Positive Technologies (AI Summary)

CVSS v3.1

9.8

Critical

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions workers-oauth-provider (affected versions not specified)

Description The issue is related to the OAuth implementation in workers-oauth-provider, part of the MCP framework. An attacker could cause the PKCE check to be skipped, completely bypassing PKCE protection. PKCE is a defense-in-depth mechanism against certain kinds of attacks and is required in the OAuth 2.1 draft, which is also required by the MCP specification.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Improper Authentication

Weakness Enumeration

CWE-287

Related Identifiers

CVE-2025-4144

GHSA-QGP8-V765-QXX9

GHSA-VH4H-FVQF-Q9WV

Affected Products

Workers-Oauth-Provider

References · 12

• https://github.com/cloudflare/workers-oauth-provider/pull/27 · Patch
• https://osv.dev/vulnerability/GHSA-qgp8-v765-qxx9 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2025-4144 · Security Note
• https://osv.dev/vulnerability/CVE-2025-4144 · Vendor Advisory
• https://osv.dev/vulnerability/GHSA-vh4h-fvqf-q9wv · Vendor Advisory
• https://github.com/cloudflare/workers-mcp · Note
• https://github.com/cloudflare/workers-oauth-provider/security/advisories/GHSA-qgp8-v765-qxx9 · Note
• https://github.com/cloudflare/workers-oauth-provider · Note
• https://twitter.com/CVEnew/status/1917775350039269494 · Twitter Post
• https://t.me/cvetracker/22775 · Telegram Post
• https://t.me/cvedetector/24175 · Telegram Post
• https://t.me/cvenotify/120425 · Telegram Post