How severe is CVE-2026-32947?

No CVSS score has been assigned to CVE-2026-32947 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-32947?

CVE-2026-32947 affects the following packages: step-security/harden-runner (GitHub Actions). Ecosystems affected: GitHub Actions.

How do I fix CVE-2026-32947?

Update step-security/harden-runner to 2.16.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-32947 is resolved across your whole dependency graph.

How do I detect CVE-2026-32947 in my GitHub Actions dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for step-security/harden-runner, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-32947 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is CVE-2026-32947 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-32947 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-32947?

CVE-2026-32947 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 24th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-32947?

CVE-2026-32947 is classified as CWE-693 (CWE-693), CWE-863 (CWE-863). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-32947 published, and has it been updated?

CVE-2026-32947 was published on March 20, 2026 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 GitHub Actions

Not in CISA KEV

CVE-2026-32947 — harden-runner

CVE-2026-32947 is a CWE-693 vulnerability in step-security/harden-runner. A fix is available for step-security/harden-runner — see the affected versions and patch details below.

Egress Policy Bypass via DNS over HTTPS (DoH) in Harden-Runner (Community Tier)

Also known asGHSA-46g3-37rh-v698

Published

Mar 20, 2026

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 5, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-32947.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs24th percentile — riskier than 24% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

📦step-security/harden-runner

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects GitHub Actions packages — download data is not available via public APIs for these ecosystems.

Description

Summary

A vulnerability exists in the Community Tier of Harden-Runner that allows bypassing the egress-policy: block network restriction using DNS over HTTPS (DoH).

Harden-Runner secures GitHub Actions workflows on runners by applying network policies, including an allowed-endpoints configuration that limits outbound traffic to specified domains and ports (e.g., github.com:443). In egress-policy: block mode, non-compliant connections are intercepted and denied.

This vulnerability exploits DoH, a protocol that encapsulates DNS queries within HTTPS requests. By crafting a DNS query that embeds exfiltrated data as a subdomain (e.g., encoding the runner's hostname into a label), an attacker can route the request through a permitted HTTPS endpoint like dns.google (8.8.8.8's DoH service). The resolver processes the query and forwards it to the attacker's controlled domain, achieving exfiltration without directly accessing the blocked destination. This evades Harden-Runner's domain-based filtering, as the initial HTTPS connection appears legitimate.

This vulnerability requires the attacker to already have code execution capabilities within the GitHub Actions workflow.

The Enterprise Tier of Harden-Runner is not affected by this vulnerability.

Impact

When Harden-Runner is configured with egress-policy: block and a restrictive allowed-endpoints list, an attacker with existing code execution capabilities within a GitHub Actions workflow can bypass the allowed domains check via DNS over HTTPS by proxying DNS queries through a permitted resolver (e.g., Google's DoH service). This allows data exfiltration even when allowed-endpoints is set to only whitelisted domains.

This vulnerability affects only the Community Tier. It requires the attacker to already have code execution capabilities within the GitHub Actions workflow.

Remediation

For Community Tier Users

Upgrade to Harden-Runner v2.16.0 or later.

For Enterprise Tier Users

No action required. Enterprise tier customers are not affected by this vulnerability.

Credit

We would like to thank Devansh Batham for responsibly disclosing this vulnerability through our security reporting process.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦GitHub Actions	`step-security/harden-runner`	all versions	2.16.0

Affected Products

1 product · 1 configurations

Application

harden-runnerstepsecurity

< 2.16.0

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for step-security/harden-runner, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update step-security/harden-runner to 2.16.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-32947 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

## Summary A vulnerability exists in the Community Tier of Harden-Runner that allows bypassing the `egress-policy: block` network restriction using DNS over HTTPS (DoH). Harden-Runner secures GitHub Actions workflows on runners by applying network policies, including an `allowed-endpoints` configuration that limits outbound traffic to specified domains and ports (e.g., `github.com:443`). In `egress-policy: block` mode, non-compliant connections are intercepted and denied. This vulnerability exploits DoH, a protocol that encapsulates DNS queries within HTTPS requests. By crafting a DNS quer