GHSA-QGP8-V765-QXX9 @cloudflare/workers-oauth-provider PKCE bypass via downgrade attack

Summary PKCE was implemented in the OAuth implementation in workers-oauth-provider that is part of MCP framework. However, it was found that an attacker could cause the check to be skipped. Impact PKCE is a defense-in-depth mechanism against certain kinds of attacks and was an optional extension ...

GHSA-VH4H-FVQF-Q9WV Duplicate Advisory: @cloudflare/workers-oauth-provider PKCE bypass via downgrade attack

Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-qgp8-v765-qxx9. This link is maintained to preserve external references. Original Description PKCE was implemented in the OAuth implementation in workers-oauth-provider that is part of MCP framework...

Duplicate Advisory: @cloudflare/workers-oauth-provider PKCE bypass via downgrade attack

Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-qgp8-v765-qxx9. This link is maintained to preserve external references. Original Description PKCE was implemented in the OAuth implementation in workers-oauth-provider that is part of MCP framework...

CVE-2025-4144

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...

CVE-2025-4144 PKCE bypass via downgrade attack

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...

CVE-2025-4144

CVE-2025-4144 affects Cloudflare’s MCP-based workers-oauth-provider. A flaw in the PKCE implementation allows an attacker to bypass PKCE verification, effectively bypassing PKCE protection. Descriptions across sources (Veracode, Red Hat, GHSA advisories, OSV) state that the OAuth check can be ski...

CVE-2025-4144 PKCE bypass via downgrade attack

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...

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

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...

GO-2022-0497 Insecure entropy in Argo CD's PKCE/Oauth2/OIDC params in github.com/argoproj/argo-cd

Insecure entropy in Argo CD's PKCE/Oauth2/OIDC params in github.com/argoproj/argo-cd...

GO-2024-2479 Authentik vulnerable to PKCE downgrade attack in goauthentik.io

Authentik vulnerable to PKCE downgrade attack in goauthentik.io. NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions. If this is causing false-positive reports from vulnerability scanners, please suggest an...

RHEL 8 : OpenShift Container Platform 4.10.51 (RHSA-2023:0560)

The remote Redhat Enterprise Linux 8 host has a package installed that is affected by multiple vulnerabilities as referenced in the RHSA-2023:0560 advisory. Red Hat OpenShift Container Platform is Red Hat's cloud computing Kubernetes application platform solution designed for on-premise or privat...

PKCE Downgrade Attack

spring-security-oauth2-authorization-server is vulnerable to PKCE Downgrade. The vulnerability is due to improper handling of PKCE authorization when a Confidential Client requests an Authorization Code Grant. Note that this vulnerability only applies to Confidential Clients, Public Clients are...

Improper Authentication in Spring Authorization Server

Spring Authorization Server versions 1.0.0 - 1.0.5, 1.1.0 - 1.1.5, 1.2.0 - 1.2.2 and older unsupported versions are susceptible to a PKCE Downgrade Attack for Confidential Clients. Specifically, an application is vulnerable when a Confidential Client uses PKCE for the Authorization Code Grant. An...

CVE-2024-22258

Spring Authorization Server versions 1.0.0 - 1.0.5, 1.1.0 - 1.1.5, 1.2.0 - 1.2.2 and older unsupported versions are susceptible to a PKCE Downgrade Attack for Confidential Clients. Specifically, an application is vulnerable when a Confidential Client uses PKCE for the Authorization Code Grant. An...

CVE-2024-22258

Spring Authorization Server versions 1.0.0 - 1.0.5, 1.1.0 - 1.1.5, 1.2.0 - 1.2.2 and older unsupported versions are susceptible to a PKCE Downgrade Attack for Confidential Clients. Specifically, an application is vulnerable when a Confidential Client uses PKCE for the Authorization Code Grant. An...

UBUNTU-CVE-2024-22258

Spring Authorization Server versions 1.0.0 - 1.0.5, 1.1.0 - 1.1.5, 1.2.0 - 1.2.2 and older unsupported versions are susceptible to a PKCE Downgrade Attack for Confidential Clients. Specifically, an application is vulnerable when a Confidential Client uses PKCE for the Authorization Code Grant. An...

CVE-2024-22258 CVE-2024-22258: PKCE Downgrade in Spring Authorization Server

Spring Authorization Server versions 1.0.0 - 1.0.5, 1.1.0 - 1.1.5, 1.2.0 - 1.2.2 and older unsupported versions are susceptible to a PKCE Downgrade Attack for Confidential Clients. Specifically, an application is vulnerable when a Confidential Client uses PKCE for the Authorization Code Grant. An...

CVE-2024-22258 CVE-2024-22258: PKCE Downgrade in Spring Authorization Server

Spring Authorization Server versions 1.0.0 - 1.0.5, 1.1.0 - 1.1.5, 1.2.0 - 1.2.2 and older unsupported versions are susceptible to a PKCE Downgrade Attack for Confidential Clients. Specifically, an application is vulnerable when a Confidential Client uses PKCE for the Authorization Code Grant. An...

CVE-2024-22258

CVE-2024-22258 affects Spring Authorization Server versions 1.0.0–1.0.5, 1.1.0–1.1.5, and 1.2.0–1.2.2 (and older unsupported) where confidential clients using PKCE with the Authorization Code Grant can be downgraded, potentially bypassing security restrictions. Public Clients using PKCE are not v...

Spring Authorization Server Security Vulnerability

VMware Spring Authorization Server is a framework for building secure OAuth 2.0 and OpenID Connect 1.0 authorization servers from VMware. A security vulnerability exists in Spring Authorization Server that stems from the vulnerability of an application to a PKCE downgrade attack when the PKCE...