EUVD-2026-34658
GHSA-549m-hfh8-j433
Severity by source
AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Primary rating from Vendor (google).
CVSS VectorVendor: google
Lifecycle Timeline
4DescriptionCVE.org
Insufficient policy enforcement in Workers in Google Chrome prior to 149.0.7827.53 allowed a remote attacker who had compromised the renderer process to bypass same origin policy via a crafted HTML page. (Chromium security severity: Medium)
AnalysisAI
Same-origin policy bypass in Google Chrome's Workers subsystem (versions prior to 149.0.7827.53) permits a remote attacker who has already compromised the renderer process to circumvent cross-origin restrictions via a crafted HTML page, resulting in high-severity integrity impact (CVSS I:H). The flaw, rooted in insufficient policy enforcement (CWE-284), functions as a second-stage chained exploit rather than an initial access vector, requiring renderer compromise as a prerequisite. No active exploitation has been identified (SSVC: exploitation none; EPSS 0.02%), and a vendor-released patch is available as of Chrome 149.0.7827.53.
Technical ContextAI
The vulnerability resides in Google Chrome's Web Workers API - the browser subsystem enabling background JavaScript execution in isolated threads, governed by the same-origin policy (SOP). SOP is the foundational browser security boundary preventing scripts from one origin accessing resources of another. CWE-284 (Improper Access Control) identifies the root cause as insufficient enforcement of this policy within the Workers context, meaning the access control gate that should block cross-origin resource access can be bypassed under exploit conditions. Critically, the attack chain requires the attacker to have already achieved renderer process compromise - positioning this vulnerability as a sandbox escalation path or policy bypass layer rather than a standalone initial compromise vector. Affected scope per EUVD-2026-34658 and vendor advisory covers all Google Chrome installations on all platforms running versions below 149.0.7827.53.
RemediationAI
Upgrade Google Chrome to version 149.0.7827.53 or later, as confirmed by the vendor's stable channel advisory at https://chromereleases.googleblog.com/2026/06/stable-channel-update-for-desktop.html. Chrome auto-updates by default for consumer installations; enterprise administrators should verify deployment via Chrome Browser Cloud Management or group policy to confirm the patched version is applied across managed fleets. No documented workarounds exist for this specific vulnerability. Given that exploitation requires a prior renderer compromise, compensating controls that reduce renderer exploit risk - such as enforcing Chrome's Site Isolation (--site-per-process, enabled by default in recent Chrome versions), restricting navigation to untrusted origins via enterprise policy, and deploying endpoint detection for browser process anomalies - can reduce the likelihood of the full attack chain succeeding. These mitigations do not address the Workers SOP bypass directly but raise the bar for the prerequisite renderer compromise stage.
Same weakness CWE-284 – Improper Access Control
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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