Site-isolation bypass via unvalidated hit-test FrameSinkId
Published May 28, 2026 · Updated May 28, 2026
Input validation failure in Google Chrome before 148.0.7778.216 allows remote attackers with a compromised renderer to bypass site isolation. The browser's asynchronous hit-test router accepts a renderer-returned FrameSinkId without confirming that its target is a descendant of the queried frame, allowing input redirection to arbitrary cross-origin frames. Exploitation requires a compromised renderer and a crafted HTML page; the documented outcome is cross-origin input redirection, not a standalone renderer compromise.
Summary
What happened
Input validation failure in Google Chrome before 148.0.7778.216 allows remote attackers with a compromised renderer to bypass site isolation. The browser's asynchronous hit-test router accepts a renderer-returned FrameSinkId without confirming that its target is a descendant of the queried frame, allowing input redirection to arbitrary cross-origin frames. Exploitation requires a compromised renderer and a crafted HTML page; the documented outcome is cross-origin input redirection, not a standalone renderer compromise.
The record
- CVE
- CVE-2026-9979
- Published
- May 28, 2026
- Updated
- May 28, 2026
- Vendor
- WebM Project
- Product
- Chrome
- Classifications
- CWE-20
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 28, 2026CVE publishedPublication date reported by the CVE source.
- May 28, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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- Affected version<148.0.7778.216
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
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Technologies
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