Google Chrome: Incorrect authorization in Accessibility enables site isolation bypass
Summary
Incorrect authorization in the Accessibility component of Google Chrome before 155.0.8059.39 allows a remote attacker to bypass site isolation. The attacker must first have compromised the renderer process, typically through another browser bug, and must lure the user to a crafted HTML page. The CVSS vector requires user interaction and no privileges, and the vulnerability is rated Medium by Chromium.
Affected
- Google Chrome prior to 155.0.8059.39
Secondary reports list different per-platform build numbers for Windows and Mac; the vendor advisory is authoritative.
Fixed in
- Google Chrome 155.0.8059.39 or later (Stable channel update of 6 October 2026)
- Later Stable builds of branch 155 are expected to include the fix; this has not been verified per build.
Workaround
- No workaround is needed when the update is applied.
- If patching is delayed, a third-party aggregator suggests enforcing site isolation via Chrome policy. This is not Google guidance and has not been verified.
Exploitation
- No evidence of exploitation in the wild found. CISA SSVC lists exploitation as none; the CISA KEV entry is unconfirmed.
- EPSS score 0.00224 (low).
- Public proof of concept: unclear.
Our recommendation
- Update Google Chrome to 155.0.8059.39 or later on all desktops and check the version under chrome://settings/help.
- Check that browsers update automatically and monitor for newer Stable releases.
- Ensure that the patch is applied to Chromium-based browsers and derivatives in use.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Chrome Releases: Stable Channel Update for Desktop chromereleases.googleblog.com
- Chromium issue tracker issues.chromium.org
- CIS Advisory: Multiple vulnerabilities in Google Chrome www.cisecurity.org
- Vulners VulnRichment: CVE-2026-106403 vulners.com
- HOL CISA ADP Vulnrichment: CVE-2026-106403 hol.org
- Malwarebytes: Update Chrome and ChromeOS to fix critical security issues www.malwarebytes.com
- OpenCVE: CVE-2026-106403 app.opencve.io
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 1 Nov 2026, 20:44.
Original description (NVD)
Incorrect authorization in Accessibility in Google Chrome prior to 155.0.8059.39 allowed a remote attacker who had compromised the renderer process to bypass site isolation via a crafted HTML page. (Chromium security severity: Medium)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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