01 Record

CVE-2026-18676

Kong Mesh: default control plane config leaks the admin token cross-origin via a CORS wildcard and localhost admin

MediumPUBLISHEDCNA: Kong

CNA base score5.1 CVSS v4.0CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

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02 Description

Kong Mesh: default control plane config leaks the admin token cross-origin via a CORS wildcard and localhost admin

03 Exploitation and scoring

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.29% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 22.2% of scored records. A rank, not a probability.

NVD base score

5.1 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

NVD analysis status

Awaiting Analysis. NVD last modified this record on 2026-10-23.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published

2026-08-12 18:42Z2 MO AGO

Last updated

2026-08-13 14:50Z2 MO AGO

Reserved

2026-08-03

Assigning CNA

Kong

Record state

PUBLISHED

Severity

Medium (CVSS 5.1)

CNA CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

Weaknesses

CWE-346Origin Validation ErrorClass
CWE-942Permissive Cross-domain Security Policy with Untrusted DomainsVariant

Data version

5.2

Document digest

a590bb45fcb513620bf69f785d08d3ead49b29c402fd833c3401ed3fd4aac57b

05 Affected products

VendorProductVersionsPlatforms

Kong Inc.Kong Mesh0 to < 2.7.25, 2.8.0 to < 2.9.15, 2.10.0 to < 2.11.13, 2.12.0 to < 2.12.10, 2.13.0 to < 2.13.5Linux

06 References

github.comUpstream advisory GHSA-3vcp-chfh-f6r2https://github.com/kumahq/kuma/security/advisories/GHSA-3vcp-chfh-f6r2vendor-advisory
github.comkumahq/kuma#16416 (master)https://github.com/kumahq/kuma/pull/16416patch
github.comkumahq/kuma#16423 (backport)https://github.com/kumahq/kuma/pull/16423patch
github.comkumahq/kuma#16424 (backport)https://github.com/kumahq/kuma/pull/16424patch
github.comkumahq/kuma#16425 (backport)https://github.com/kumahq/kuma/pull/16425patch
github.comkumahq/kuma#16426 (backport)https://github.com/kumahq/kuma/pull/16426patch
github.comkumahq/kuma#16427 (backport)https://github.com/kumahq/kuma/pull/16427patch
developer.konghq.comKong MESH Changeloghttps://developer.konghq.com/mesh/changelog/release-notes

07 Remediation

Upgrade to Kong Mesh 2.7.25, 2.9.15, 2.11.13, 2.12.10 or 2.13.5, whichever matches your release line. In patched versions the corsAllowedDomains default changed from [".*"] to [], making CORS opt-in, and localhostIsAdmin was hardened to require a direct loopback RemoteAddr and Host and to reject requests carrying proxy-hop headers (X-Forwarded-For), cross-site fetch metadata (Sec-Fetch-Site), or a non-localhost Origin. The 2.14 line shipped after the fix and was never affected.