Admin credential disclosure via permissive loopback CORS
Published Aug 12, 2026 · Updated Aug 12, 2026
Origin validation errors in Kong Mesh kuma-cp allow remote attackers to obtain admin tokens and signing keys through a malicious webpage. The default CORS wildcard reflects any Origin, while localhostIsAdmin promotes loopback requests to mesh-system:admin and returns the admin JWT and signing material. Exploitation requires default settings, browser reachability to the control plane on the same machine, and an operator visiting attacker-controlled JavaScript.
Summary
What happened
Origin validation errors in Kong Mesh kuma-cp allow remote attackers to obtain admin tokens and signing keys through a malicious webpage. The default CORS wildcard reflects any Origin, while localhostIsAdmin promotes loopback requests to mesh-system:admin and returns the admin JWT and signing material. Exploitation requires default settings, browser reachability to the control plane on the same machine, and an operator visiting attacker-controlled JavaScript.
The record
- CVE
- CVE-2026-18676
- Published
- Aug 12, 2026
- Updated
- Aug 12, 2026
- Vendor
- Kong Inc.
- Product
- Kong Mesh
- Classifications
- CWE-346, CWE-942, T1189
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 12, 2026CVE publishedPublication date reported by the CVE source.
- Aug 12, 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.
- Affected versionversion=0 <2.7.25
- Affected versionversion=2.10.0 <2.11.13
- Affected versionversion=2.12.0 <2.12.10
- Affected versionversion=2.13.0 <2.13.5
- Affected versionversion=2.8.0 <2.9.15
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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