CVE-2026-9891
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedUse after free in Extensions in Google Chrome prior to 148.0.7778.216 allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape via a crafted Chrome Extension. (Chromium security severity: Critical)
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceA use-after-free vulnerability in Google Chrome's Extensions component prior to version 148.0.7778.216 allows a remote attacker who has already compromised the renderer process to potentially escape the browser's sandbox via a crafted Chrome Extension.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 148.0.7778.216< 148.0.7778.215CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- High
- Privileges
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check installed Chrome versionNavigate to chrome://version in the Chrome browser and look at the 'Chrome' field, or run 'google-chrome --version' from command lineAffected if The version listed is less than 148.0.7778.216 (for stable) or less than 148.0.7778.215 (for the specific branch)
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Confirm the Extensions component is presentOpen chrome://extensions, ensure the extensions management page loads and extensions are visibleAffected if Extensions UI loads successfully, indicating the Extensions component is active and available for exploitation
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Verify renderer process context existsThis vulnerability requires a compromised renderer process - check for unexpected or suspicious extensions loaded in chrome://extensions, or review extension developer mode statusAffected if Any extensions are installed and enabled, particularly from untrusted sources, which could provide the attack surface for a compromised renderer to interact with the Extensions component
You are affected if your Chrome version is earlier than 148.0.7778.216 and you have any extensions loaded, since the use-after-free in the Extensions component requires both an older vulnerable version and active extension functionality for a sandbox-escaping attack.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped148.0.7778.215148.0.7778.216
Update Google Chrome to version 148.0.7778.216 or later, or ensure automatic updates are enabled to receive the security patch.
Chrome 148.0.7778.216 or later
- Open Chrome browser and navigate to Settings > Help > About Google Chrome
- Chrome will automatically check for and install the latest version
- Restart the browser after the update completes
- Verify the version by going to chrome://settings/help - ensure it shows version 148.0.7778.216 or later
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,696.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-9891 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-9891 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data