CVE-2026-32946: medium-severity vulnerability in step-security harden-runner
Egress Policy Bypass via DNS over TCP in Harden-Runner (Community Tier)
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 4.6epss 0.3%
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.
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
Affected products
step-security · harden-runnerRelated CVEs — step-security harden-runner
In the same product, most dangerous first.
CVE-2024-52587LOWHarden-Runner has command injection weaknesses in `setup.ts` and `arc-runner.ts`EPSS 2.8%CVE-2026-25598MEDIUMBypassing Logging of Outbound Connections Using sendto, sendmsg, and sendmmsg in Harden-Runner (Community Tier)EPSS 0.3%CVE-2026-32947MEDIUMEgress Policy Bypass via DNS over HTTPS (DoH) in Harden-Runner (Community Tier)EPSS 0.3%CVE-2025-32955MEDIUMHarden-Runner Evasion of 'disable-sudo' policyEPSS 0.2%