CVE-2026-32947: Harden-Runner is a CI/CD security agent that works like an EDR for GitHub Actions runners

Q: How do I fix CVE-2026-32947?

harden-runner: upgrade to 2.16.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-32947 being exploited?

CVE-2026-32947 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-32947 affect?

CVE-2026-32947 affects harden-runner. Severity is medium (CVSS 4.9). Harden-Runner is a CI/CD security agent that works like an EDR for GitHub Actions runners. In versions 2.15.1 and below, a DNS over HTTPS (DoH) vulnerability allows attackers to bypass egress-policy: block network restrictions by tunneling

Q: How urgent is CVE-2026-32947?

Priority 23/100. No elevated risk signals yet.

Routine

MEDIUM 4.9UPGRADE

CVE-2026-32947 is a medium-severity flaw (CVSS 4.9) affecting harden-runner. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Harden-Runner is a CI/CD security agent that works like an EDR for GitHub Actions runners. In versions 2.15.1 and below, a DNS over HTTPS (DoH) vulnerability allows attackers to bypass egress-policy: block network restrictions by tunneling exfiltrated data through permitted HTTPS endpoints like dns.google. The attack works by encoding sensitive data (e.g., the runner's hostname) as subdomains in DoH queries, which appear as legitimate HTTPS traff

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	4.9 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	High
User interaction	None
EPSS exploit chance	0.3% (top 76%)
CISA exploited list	No
Weakness	CWE-693, CWE-863
Published	2026-03-20
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: stepsecurity

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-03-20 05:16 UTCPublished CVE record published
2026-06-17 10:36 UTCUpdated Record last modified

stepsecurity harden-runner UPGRADE

Affected: < 2.16.0

Fixed in: 2.16.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy harden-runner || rpm -q harden-runner || harden-runner --version

2. UPGRADE to 2.16.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade harden-runner

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade harden-runner

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-32947?

harden-runner: upgrade to 2.16.0. Exact commands for each OS are on this page.

Is CVE-2026-32947 being exploited?

CVE-2026-32947 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-32947 affect?

CVE-2026-32947 affects harden-runner. Severity is medium (CVSS 4.9). Harden-Runner is a CI/CD security agent that works like an EDR for GitHub Actions runners. In versions 2.15.1 and below, a DNS over HTTPS (DoH) vulnerability allows attackers to bypass egress-policy: block network restrictions by tunneling

How urgent is CVE-2026-32947?

Priority 23/100. No elevated risk signals yet.

Software pages

GitHub vulnerabilities

Related CVEs

CVE-2026-32946 LOW 2.7 UPGRADE Harden-Runner is a CI/CD security agent that works like an EDR for GitHub Actions runners

References

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