Google Chrome: Use-after-free in FedCM allows code execution outside sandbox
Summary
A use-after-free vulnerability in the FedCM (Federated Credential Management) feature of Google Chrome desktop allows a remote attacker to execute arbitrary code outside the browser sandbox. The attacker needs to lure a user to a crafted HTML page, and the user must interact with it. Google rates the issue as High severity; CVSS 3.1 is 9.6 (Critical).
Affected
- Google Chrome desktop builds prior to 154.0.8037.97 (Windows, macOS, Linux)
Fixed in
- Google Chrome 154.0.8037.97 or later (Stable channel update of 1 October 2026)
- Linux distributions publish their own package versions; check your distribution advisory
Workaround
- Unknown. No vendor workaround is documented for this issue. Updating Chrome is the recommended fix.
Exploitation
- No known exploitation in the wild according to the sources reviewed. CISA SSVC: Exploitation none, Automatable no, Technical Impact total.
- An AI-lab research write-up describes a use-after-free in FedCM used in an exploit chain; it is not confirmed that this is CVE-2026-103630.
Our recommendation
- Update Google Chrome to 154.0.8037.97 or later, or the current stable release, on all endpoints.
- Check Chromium-based browsers such as Edge and Brave, which ship their own updates.
- Verify the rollout via MDM or Chrome policies and confirm the version at chrome://version.
- Prioritise patching, because the browser is reachable from any web page.
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
- OSV: DEBIAN-CVE-2026-103630 osv.dev
- Vulners: CVELIST CVE-2026-103630 vulners.com
- Vulners: EUVD-2026-91709 vulners.com
- CISA ADP Vulnrichment summary (HOL Guard) hol.org
- Chrome security update 154 (SecurityOnline) securityonline.info
- Discovering vulnerabilities with Claude (Anthropic) www.anthropic.com
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 30 Oct 2026, 23:26.
Original description (NVD)
Use after free in FedCM in Google Chrome prior to 154.0.8037.97 allowed a remote attacker to execute arbitrary code outside the sandbox via a crafted HTML page. (Chromium security severity: High)
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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