# CVE-2026-26055: Unauthenticated Admission Webhook Endpoints in Yoke ATC

> Unauthenticated webhook endpoints in Yoke ATC allow cluster pods to trigger WASM execution, enabling unauthorized code execution and privilege escalation.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Feb 2026
- **Updated:** 12 Feb 2026
- **Also known as:** GHSA-965m-v4cc-6334, GO-2026-4491

## What is CVE-2026-26055?

CVE-2026-26055 is a high-severity missing authorization vulnerability in yokecd yoke, published on 12 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Yoke is a Helm-inspired infrastructure-as-code (IaC) package deployer. In 0.19.0 and earlier, a vulnerability exists in the Air Traffic Controller (ATC) component of Yoke. The ATC webhook endpoints lack proper authentication mechanisms, allowing any pod within the cluster network to directly send AdmissionReview requests to the webhook, bypassing Kubernetes API Server authentication. This enables attackers to trigger WASM module execution in the ATC controller context without proper authorization.

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2026-26055?

3 open source packages ship an affected version, including github.com/yokecd/yoke. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/yokecd/yoke` | Go | All versions | None |
| `github.com/yokecd/yoke` | Go | All versions to 0.19.0 | None |
| `github.com/yokecd/yoke` | Go | All versions to 0.19.0 | None |

Products: Yokecd Yoke.

## How do I fix CVE-2026-26055?

Upgrade to a fixed version.

## Is CVE-2026-26055 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-26055 exists.

## Other vulnerabilities in yokecd yoke

- [CVE-2026-26056](https://insights.sbomify.com/CVE-2026-26056/): Arbitrary WASM Code Execution via AnnotationOverrideFlight Injection in Yoke ATC (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-26055 and fix it if it is affected.

What it is: CVE-2026-26055 is a high-severity missing authorization vulnerability in yokecd yoke, published on 12 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-26055 exists.

Affected packages and fixed versions:
- github.com/yokecd/yoke (Go): affected all versions; no fix listed
- github.com/yokecd/yoke (Go): affected all versions up to 0.19.0; no fix listed
- github.com/yokecd/yoke (Go): affected all versions up to 0.19.0; no fix listed

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-2026-26055/ (Markdown: https://insights.sbomify.com/CVE-2026-26055/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-26055
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-26055
- OSV: https://osv.dev/vulnerability/CVE-2026-26055

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-26055/
Summaries are generated and may contain mistakes; the official description above is the record.