Cross-Site WebSocket Hijacking in Google Cloud Shell

published 2026-10-20 20 d ago modified 2026-10-20 19 d ago also EUVD-2026-104858

cvss: 8.7; 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 11%
public exploits: 0; none known

A Cross-Site WebSocket Hijacking vulnerability in Cloud Shell prior to 2026-07-22 on Google Cloud Platform allows an unauthenticated attacker to hijack an active Cloud Shell session and exfiltrate the user's OAuth access token using a cross-origin WebSocket request.

This vulnerability was patched on 22 July 2026, and no customer action is needed.

Patch / fix

fixed in 1

Google Cloud Cloud Shell 2026-07-22

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-85267 updated 2026-11-05 cvss 8.8

Cloud Shell: Cloud Shell: Session hijacking via cross-origin WebSocket requests

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 19 d ago (2026-10-20)

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	8.7	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/U:Clear
CNA	4.0	8.7	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/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 Cloud Shell

Classification

Weakness

CWE-1385 Missing Origin Validation in WebSockets

References

docs.cloud.google.com /shell/docs/release-notes#July_28_2026

Sources

CVE List CVE-2026-85267
NVD CVE-2026-85267

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