# CVE-2026-32946: Egress Policy Bypass via DNS over TCP in Harden-Runner (Community Tier)

> Attackers with code execution can bypass egress network restrictions by using TCP-based DNS queries, evading security controls in Harden-Runner.

- **Severity:** Medium 4.6 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 20 Mar 2026
- **Updated:** 20 Mar 2026
- **Also known as:** GHSA-g699-3x6g-wm3g

## What is CVE-2026-32946?

CVE-2026-32946 is a medium-severity vulnerability in step-security harden-runner, published on 20 Mar 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

Harden-Runner is a CI/CD security agent that works like an EDR for GitHub Actions runners. In versions 2.15.1 and below, the Harden-Runner that allows bypass of the egress-policy: block network restriction using DNS queries over TCP. Egress policies are enforced on GitHub runners by filtering outbound connections at the network layer. When egress-policy: block is enabled with a restrictive allowed-endpoints list (e.g., only github.com:443), all non-compliant traffic should be denied. However, DNS queries over TCP, commonly used for large responses or fallback from UDP, are not adequately restricted. Tools like dig can explicitly initiate TCP-based DNS queries (+tcp flag) without being blocked. This vulnerability requires the attacker to already have code execution capabilities within the GitHub Actions workflow. The issue has been fixed in version 2.16.0.

Weakness: CWE-863 (Incorrect Authorization), CWE-693 (Protection Mechanism Failure)

## Which versions are affected by CVE-2026-32946?

1 open source package ship an affected version, including step-security/harden-runner. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `step-security/harden-runner` | GitHub Actions | All versions | 2.16.0 |

Products: Stepsecurity Harden-Runner.

## How do I fix CVE-2026-32946?

Upgrade step-security/harden-runner to 2.16.0 or later.

## Is CVE-2026-32946 being exploited?

There is no known exploitation of CVE-2026-32946 in the wild and no public exploit code.

## Other vulnerabilities in step-security harden-runner

- [CVE-2026-25598](https://insights.sbomify.com/CVE-2026-25598/): Bypassing Logging of Outbound Connections Using sendto, sendmsg, and sendmmsg in Harden-Runner (Community Tier) (medium 6.3)
- [CVE-2026-32947](https://insights.sbomify.com/CVE-2026-32947/): Egress Policy Bypass via DNS over HTTPS (DoH) in Harden-Runner (Community Tier) (medium 4.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-32946 and fix it if it is affected.

What it is: CVE-2026-32946 is a medium-severity vulnerability in step-security harden-runner, published on 20 Mar 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-32946 in the wild and no public exploit code.

Affected packages and fixed versions:
- step-security/harden-runner (GitHub Actions): affected all versions; fixed in 2.16.0

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-2026-32946/ (Markdown: https://insights.sbomify.com/CVE-2026-32946/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-32946
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-32946
- OSV: https://osv.dev/vulnerability/CVE-2026-32946

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-32946/
Summaries are generated and may contain mistakes; the official description above is the record.