Google Cloud Build Comment Control Bypass via Webhook Suppression

published 2026-08-31 2 mo ago modified 2026-08-31 2 mo ago also EUVD-2026-68433

cvss: 9.4; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 9%
public exploits: 0; none known

An Incorrect Authorization vulnerability in GitHub Trigger Comment Control in Google Cloud Build prior to 2026-06-24 on Google Cloud Platform allows a remote attacker to execute unreviewed code in the build environment using webhook suppression.

This vulnerability was patched on 24 June 2026, and no customer action is needed.

Patch / fix

fixed in 1

Google Cloud Google Cloud Build 2026-06-24

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 2 mo ago (2026-08-31)

Exploit prediction

0.20% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	9.4	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/U:Clear
CNA	4.0	9.4	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Clear

Affected products

Google Cloud Google Cloud Build

Classification

Weakness

CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition
CWE-345 Insufficient Verification of Data Authenticity

References

docs.cloud.google.com /build/docs/release-notes#August_24_2026

Sources

CVE List CVE-2026-19410
NVD CVE-2026-19410

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary