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Mallory
Critical

Sandbox escape use-after-free in Google Chrome Extensions

IdentifiersCVE-2026-9891CWE-416· Use After Free

CVE-2026-9891 is a use-after-free vulnerability in the Extensions component of Google Chrome affecting versions prior to 148.0.7778.216. According to the provided advisory text, a remote attacker who has already compromised the renderer process could trigger the flaw via a crafted Chrome Extension and potentially escape Chrome's sandbox. The issue is rated Critical by Chromium. No specific vulnerable function or code path is provided in the supplied content.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation could allow an attacker who already achieved renderer-process compromise to break out of the browser sandbox. This can enable escalation from a renderer compromise to broader code execution in a more privileged browser context, undermining Chrome's process isolation and potentially enabling further system compromise depending on the host environment and follow-on exploit chain.

Mitigation

If you can’t patch tonight, do this now.

No specific workaround is provided in the supplied content. The practical mitigation is to apply the vendor patch as soon as available. Until patched, reducing exposure to untrusted extensions and limiting opportunities for renderer compromise may reduce risk, but the provided advisories do not document an official temporary mitigation.

Remediation

Patch, then assume compromise.

Upgrade Google Chrome to version 148.0.7778.216 or later. For Debian chromium, upgrade to 148.0.7778.215-1~deb12u1 on oldstable (bookworm) or 148.0.7778.215-1~deb13u1 on stable (trixie), as referenced in the provided advisory content.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
GoogleChromeapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

1 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.
Exposure mapping

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Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity

Community discussion across Reddit, Mastodon, and other social sources.