# CVE-2026-18677: Kong Mesh: a dataplane token without a workload binding can claim any workload's SPIFFE identity

> Attackers can impersonate any workload and obtain its SPIFFE identity in Kong Mesh universal mode if workload binding is optional.

- **Severity:** Medium 6.0 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 Aug 2026
- **Updated:** 13 Aug 2026
- **Also known as:** GHSA-6p7w-xxw9-j47f, GHSA-744g-c785-x65q

## What is CVE-2026-18677?

CVE-2026-18677 is a medium-severity authentication bypass vulnerability in Kong Mesh, published on 12 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

In Kong Mesh running in universal mode with a MeshIdentity whose SPIFFE ID path template derives from the dataplane's kuma.io/workload label, the XDS authenticator in kuma-cp validates that label only when the dataplane token is bound to a workload. Workload binding is optional, so a dataplane presenting a tags-bound token can register with kuma.io/workload set to any value and obtain another workload's SPIFFE identity.

Weakness: CWE-290 (Authentication Bypass by Spoofing)

## Which versions are affected by CVE-2026-18677?


## How do I fix CVE-2026-18677?

No fix has been published for CVE-2026-18677 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-18677 being exploited?

There is no known exploitation of CVE-2026-18677 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-18677 and fix it if it is affected.

What it is: CVE-2026-18677 is a medium-severity authentication bypass vulnerability in Kong Mesh, published on 12 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-18677 in the wild and no public exploit code.

Affected product: Kong Mesh. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-18677/ (Markdown: https://insights.sbomify.com/CVE-2026-18677/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-18677
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-18677
- OSV: https://osv.dev/vulnerability/CVE-2026-18677

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-18677/
Summaries are generated and may contain mistakes; the official description above is the record.