CVE-2026-25598Network attack vector

Audit-log bypass via unmonitored socket system calls

Published Feb 9, 2026 · Updated Feb 9, 2026

Insufficient logging in Harden-Runner Community Tier before 2.14.2 allows attackers to hide outbound UDP traffic from audit logs. The agent omits sendto, sendmsg, and sendmmsg socket system calls from its audit coverage, so native workflow code can transmit UDP data without generating network events. Exploitation requires code execution in a workflow configured with egress-policy audit; block mode and the Enterprise Tier remain unaffected.

CVSS severity6.3
Medium
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Insufficient logging in Harden-Runner Community Tier before 2.14.2 allows attackers to hide outbound UDP traffic from audit logs. The agent omits sendto, sendmsg, and sendmmsg socket system calls from its audit coverage, so native workflow code can transmit UDP data without generating network events. Exploitation requires code execution in a workflow configured with egress-policy audit; block mode and the Enterprise Tier remain unaffected.

The record

CVE
CVE-2026-25598
Published
Feb 9, 2026
Updated
Feb 9, 2026
Vendor
StepSecurity
Product
Harden-Runner
Classifications
CWE-778, T1211
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 9, 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=< 2.14.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

StepSecurity · Harden-Runnerversion=< 2.14.2

Published CVSS scores

6.3GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/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.

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-778Insufficient Logging
T1211Exploitation for Stealth

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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