CVE-2026-3136Network attack vector

Unauthenticated code execution via comment-control bypass

Published Mar 3, 2026 · Updated Mar 3, 2026

Improper authorization in Google Cloud Build before 1/26/2026 allows remote attackers to execute arbitrary code in the build environment. The affected GitHub Trigger Comment Control path is intended to require approval from a repository writer, but Google has not published the faulty internal operation. Exploitation requires a GitHub pull-request interaction and grants code execution within the victim build environment.

CVSS severity8.6
High
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authorization in Google Cloud Build before 1/26/2026 allows remote attackers to execute arbitrary code in the build environment. The affected GitHub Trigger Comment Control path is intended to require approval from a repository writer, but Google has not published the faulty internal operation. Exploitation requires a GitHub pull-request interaction and grants code execution within the victim build environment.

The record

CVE
CVE-2026-3136
Published
Mar 3, 2026
Updated
Mar 3, 2026
Vendor
Go standard library
Product
Cloud Build
Classifications
CWE-863, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 3, 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=0 <1/26/2026

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Go standard library · Cloud Buildversion=0 <1/26/2026

Published CVSS scores

8.6Google CloudCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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-863Incorrect Authorization
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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