9.9
CRITICAL CVSS 3.1
CVE-2026-61682
kcp front-proxy does not strip inbound X-Remote-* identity headers, allowing any authenticated client to inject groups/warrants and impersonate system:masters in any workspace
Description

kcp is a Kubernetes-like control plane for form-factors and use-cases beyond Kubernetes and container workloads. Prior to 0.31.4 and 0.32.2, the kcp front-proxy does not remove inbound X-Remote-User, X-Remote-Group, or X-Remote-Extra-* identity headers before forwarding requests to shards. Any authenticated tenant can inject X-Remote-Group: system:masters, authorization.kcp.io/warrant, authentication.kcp.io/scopes, or a group used for per-workspace required-group gating, and the shard trusts these values as authenticated identity assertions. This allows cross-workspace impersonation, authorization bypass, and arbitrary reading, writing, or deletion of resources, secrets, RBAC data, APIExports, APIBindings, and LogicalClusters. This issue is fixed in versions 0.31.4 and 0.32.2.

INFO

Published Date :

Sept. 18, 2026, 4:17 p.m.

Last Modified :

Sept. 18, 2026, 4:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-61682 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
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 CRITICAL [email protected]
Solution
Update kcp to a patched version to prevent identity header impersonation and bypass.
  • Update kcp to version 0.31.4 or 0.32.2.
  • Ensure the front-proxy properly removes identity headers.
References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-61682 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-2026-61682 weaknesses.

CAPEC-21: Exploitation of Trusted Identifiers Exploitation of Trusted Identifiers CAPEC-22: Exploiting Trust in Client Exploiting Trust in Client CAPEC-59: Session Credential Falsification through Prediction Session Credential Falsification through Prediction CAPEC-60: Reusing Session IDs (aka Session Replay) Reusing Session IDs (aka Session Replay) CAPEC-94: Adversary in the Middle (AiTM) Adversary in the Middle (AiTM) CAPEC-459: Creating a Rogue Certification Authority Certificate Creating a Rogue Certification Authority Certificate CAPEC-461: Web Services API Signature Forgery Leveraging Hash Function Extension Weakness Web Services API Signature Forgery Leveraging Hash Function Extension Weakness CAPEC-473: Signature Spoof Signature Spoof CAPEC-476: Signature Spoofing by Misrepresentation Signature Spoofing by Misrepresentation CAPEC-667: Bluetooth Impersonation AttackS (BIAS) Bluetooth Impersonation AttackS (BIAS) CAPEC-10: Buffer Overflow via Environment Variables Buffer Overflow via Environment Variables CAPEC-13: Subverting Environment Variable Values Subverting Environment Variable Values CAPEC-21: Exploitation of Trusted Identifiers Exploitation of Trusted Identifiers CAPEC-31: Accessing/Intercepting/Modifying HTTP Cookies Accessing/Intercepting/Modifying HTTP Cookies CAPEC-39: Manipulating Opaque Client-based Data Tokens Manipulating Opaque Client-based Data Tokens CAPEC-45: Buffer Overflow via Symbolic Links Buffer Overflow via Symbolic Links CAPEC-77: Manipulating User-Controlled Variables Manipulating User-Controlled Variables CAPEC-274: HTTP Verb Tampering HTTP Verb Tampering CAPEC-73: User-Controlled Filename User-Controlled Filename CAPEC-76: Manipulating Web Input to File System Calls Manipulating Web Input to File System Calls CAPEC-85: AJAX Footprinting AJAX Footprinting CAPEC-141: Cache Poisoning Cache Poisoning CAPEC-142: DNS Cache Poisoning DNS Cache Poisoning

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).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-61682 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-61682 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]

    Sep. 18, 2026

    Action Type Old Value New Value
    Added Description kcp is a Kubernetes-like control plane for form-factors and use-cases beyond Kubernetes and container workloads. Prior to 0.31.4 and 0.32.2, the kcp front-proxy does not remove inbound X-Remote-User, X-Remote-Group, or X-Remote-Extra-* identity headers before forwarding requests to shards. Any authenticated tenant can inject X-Remote-Group: system:masters, authorization.kcp.io/warrant, authentication.kcp.io/scopes, or a group used for per-workspace required-group gating, and the shard trusts these values as authenticated identity assertions. This allows cross-workspace impersonation, authorization bypass, and arbitrary reading, writing, or deletion of resources, secrets, RBAC data, APIExports, APIBindings, and LogicalClusters. This issue is fixed in versions 0.31.4 and 0.32.2.
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
    Added CWE CWE-290
    Added CWE CWE-302
    Added CWE CWE-348
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/61xxx/CVE-2026-61682.json">CVE-2026-61682</a>
    Added Reference https://github.com/kcp-dev/kcp/commit/7437cdcfec8f927d1a9bf1b2dd1e075d038e27ca
    Added Reference https://github.com/kcp-dev/kcp/commit/f913ee890fb2fd9fa78e50c43474b078bfb6aeff
    Added Reference https://github.com/kcp-dev/kcp/releases/tag/v0.31.4
    Added Reference https://github.com/kcp-dev/kcp/releases/tag/v0.32.2
    Added Reference https://github.com/kcp-dev/kcp/security/advisories/GHSA-c8w2-fgvx-vhv4
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.