CVE-2026-61682Network attack vector

Authenticated authorization bypass via trusted identity headers

Published Sep 18, 2026 · Updated Sep 18, 2026

Authentication bypass in kcp before 0.31.4 and 0.32.0 through 0.32.1 allows remote authenticated users to read, write, or delete workspace resources. The front-proxy appends authenticated identity headers without first removing client-supplied X-Remote-User, X-Remote-Group, and X-Remote-Extra-* values, and shards trust the resulting values. Any ordinary tenant credential suffices to impersonate system:masters across a shard and control other tenants' resources.

CVSS severity9.9
Critical
EPSS probability0.38%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in kcp before 0.31.4 and 0.32.0 through 0.32.1 allows remote authenticated users to read, write, or delete workspace resources. The front-proxy appends authenticated identity headers without first removing client-supplied X-Remote-User, X-Remote-Group, and X-Remote-Extra-* values, and shards trust the resulting values. Any ordinary tenant credential suffices to impersonate system:masters across a shard and control other tenants' resources.

The record

CVE
CVE-2026-61682
Published
Sep 18, 2026
Updated
Sep 18, 2026
Vendor
kcp
Product
kcp
Classifications
CWE-302, CWE-348, CWE-290, T1078
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.31.4
  2. Affected versionversion=>= 0.32.0, < 0.32.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

kcp · kcpversion=< 0.31.4; version=>= 0.32.0, < 0.32.2

Published CVSS scores

9.9GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-302Authentication Bypass by Assumed-Immutable Data
CWE-348Use of Less Trusted Source
CWE-290Authentication Bypass by Spoofing
T1078Valid Accounts

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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