CVE-2026-32946Network attack vector

Network restriction bypass via unrestricted TCP DNS

Published Mar 20, 2026 · Updated Mar 20, 2026

Protection failure in StepSecurity Harden-Runner 2.15.1 and earlier allows attackers to bypass egress restrictions via TCP DNS queries. The Community Tier network filter permits TCP connections to external DNS resolvers even when block policy and allowed endpoints should deny them. Existing workflow code execution and that restrictive configuration are required, enabling unauthorized outbound communication and data exfiltration.

CVSS severity4.6
Medium
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Protection failure in StepSecurity Harden-Runner 2.15.1 and earlier allows attackers to bypass egress restrictions via TCP DNS queries. The Community Tier network filter permits TCP connections to external DNS resolvers even when block policy and allowed endpoints should deny them. Existing workflow code execution and that restrictive configuration are required, enabling unauthorized outbound communication and data exfiltration.

The record

CVE
CVE-2026-32946
Published
Mar 20, 2026
Updated
Mar 20, 2026
Vendor
StepSecurity
Product
Harden-Runner
Classifications
CWE-693, CWE-863, T1048.003
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Mar 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 2.16.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

StepSecurity · Harden-Runnerversion=< 2.16.0

Published CVSS scores

4.6GitHub, Inc.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
2.7NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-693Protection Mechanism Failure
CWE-863Incorrect Authorization
T1048.003Exfiltration Over Unencrypted Non-C2 Protocol

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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