EUVD-2026-34635
GHSA-rf7q-c3fx-f2jj
Severity by source
AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N
Primary rating from Vendor (google).
CVSS VectorVendor: google
Lifecycle Timeline
4DescriptionCVE.org
Inappropriate implementation in Site Isolation in Google Chrome prior to 149.0.7827.53 allowed a remote attacker who had compromised the renderer process to bypass site isolation via a crafted HTML page. (Chromium security severity: Medium)
AnalysisAI
Site Isolation bypass in Google Chrome prior to 149.0.7827.53 enables a remote attacker - who has already compromised the renderer process - to escape cross-origin protections via a crafted HTML page, exposing high-confidentiality data from other origins loaded in the browser. This is a chained, second-stage exploit component: it does not function standalone but amplifies the impact of a separate renderer compromise by breaking Chrome's primary cross-site data isolation boundary. No public exploit code has been identified at time of analysis, and the EPSS score of 0.02% (4th percentile) reflects low current exploitation probability despite the high confidentiality impact rating.
Technical ContextAI
Google Chrome's Site Isolation feature enforces the security policy that each web origin is rendered in its own isolated process, preventing cross-origin memory reads and protecting credentials, cookies, and DOM content from other tabs or frames. CWE-693 (Protection Mechanism Failure) identifies the root cause as a flaw in the implementation of this isolation mechanism - not a logic error in policy enforcement but an inappropriate implementation within the Site Isolation subsystem itself. When a renderer process is already under attacker control, this flaw allows crafted HTML to manipulate or escape the isolation boundary in a way the security model should prohibit. Affected versions are all Google Chrome releases prior to 149.0.7827.53 across desktop platforms, as identified in the ENISA EUVD entry EUVD-2026-34635 and the Google Chrome Releases advisory.
RemediationAI
Update Google Chrome to version 149.0.7827.53 or later, which contains the vendor-released patch addressing this Site Isolation implementation flaw. The update is available via Chrome's built-in auto-update mechanism or directly from https://chromereleases.googleblog.com/2026/06/stable-channel-update-for-desktop.html. For enterprise environments using managed Chrome deployments, prioritize pushing this update through policy, particularly for users accessing sensitive cross-origin content such as financial portals, authentication flows, or internal web applications. As a compensating control prior to patching, enabling Chrome's strict site isolation policy (--site-per-process is default in modern Chrome but can be enforced via enterprise policy) does not mitigate this flaw since the vulnerability is within that very subsystem. Restricting browsing to trusted origins and deploying endpoint detection capable of identifying anomalous cross-origin resource access are the most actionable interim controls, though both carry usability and coverage trade-offs.
Same weakness CWE-693 – Protection Mechanism Failure
View allSame technique Authentication Bypass
View allVendor StatusVendor
SUSE
Severity: Medium| Product | Status |
|---|---|
| openSUSE Tumbleweed | Fixed |
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External POC / Exploit Code
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