CVE-2026-106227

Executive Summary

CVE-2026-106227 is a use-after-free (CWE-416) vulnerability in the Core component of Google Chrome affecting versions prior to 155.0.8059.39. The flaw is remotely triggerable via a crafted HTML page and permits an attacker to execute arbitrary code outside the browser sandbox. With a CVSS v3.1 base score of 9.6 and a Chromium security severity rating of High, the issue is significant for any organization whose workforce relies on Chrome as its primary browser.

Technical Analysis

The vulnerability is classified as a use-after-free in Chrome Core. Use-after-free arises when a program continues to reference a memory object after it has been released, allowing an attacker who can influence heap layout and object lifecycle to redirect execution through attacker-controlled data. In a browser context, this class of bug is reachable from a renderer process processing attacker-supplied web content.

The NVD description states that exploitation occurs via a crafted HTML page, meaning the attack surface is the normal web rendering pipeline, not a privileged local interface. The most important qualitative fact is the scope of impact: successful exploitation allows code execution "outside the sandbox." Chaining a memory-corruption primitive in a renderer into code execution outside the sandbox implies that either the flaw exists in a component that operates at a higher privilege level, or the renderer compromise is used as a pivot. The description does not identify the specific function, object, or class involved, and no CNA title was provided. Accordingly, no code-level symbol, member, or subsystem name should be assumed beyond "Core."

The CVSS vector confirms the risk profile: AV:N (network reachable), AC:L (low attack complexity), PR:N (no privileges required), UI:R (user must interact, consistent with visiting a page), S:C (scope changed — the vulnerable component's compromise affects resources beyond its security authority), and C:H/I:H/A:H (high confidentiality, integrity, and availability impact). The UI:R requirement means exploitation is not fully autonomous; it depends on the victim loading the crafted page.

Because the vulnerability class is memory corruption, exploit reliability against a modern browser hardening stack typically depends on additional primitives (for example, heap grooming and ASLR bypass). The provided data contains no evidence of a public proof-of-concept, no exploit code, and no Nuclei template. No vendor fix, workaround, affected-version package list, or patch source is available in the supplied intelligence.

Exploitation Scenarios

No public PoC is available; the attack chain below is inferred from the vulnerability class and the NVD description, and does not assume any function, API, or file path not stated in the source data.

1. Reconnaissance and target identification. The attacker identifies victims running Chrome versions below 155.0.8059.39. This can be done through passive fingerprinting (browser version exposed in HTTP User-Agent or JavaScript feature probing) or by serving the exploit universally and relying on version-conditional gating.

2. Delivery and trigger. The attacker hosts or injects a crafted HTML page and induces the victim to load it — via phishing link, malicious advertisement, compromised legitimate site, or watering-hole placement. Loading the page is the sole user interaction required, consistent with UI:R in the CVSS vector. The page exercises the vulnerable Core code path and causes a memory object to be freed while still referenced.

3. Memory corruption to code execution. The dangling reference is reused, corrupting memory in a way the attacker controls through page-supplied data. The attacker leverages this corruption to gain control of execution flow within the browser process context.

4. Sandbox escape and post-exploitation. Per the NVD description, the outcome is arbitrary code execution outside the sandbox. From the OS-level context, the attacker can read and exfiltrate data accessible to the browser user, install persistence, escalate privileges, or use the host as a foothold for lateral movement. Given S:C in the CVSS vector, the impact extends beyond the initially vulnerable component's security boundary.

The uncertainty in this chain is exploitability engineering, not attack concept: nothing in the provided data indicates a working public exploit exists, and no in-the-wild exploitation, CISA KEV listing, or threat-actor campaign is reported.

Impact Assessment

Business impact is potentially severe for any environment where Chrome is a primary or mandated browser. The CVSS base score of 9.6 reflects a critical-severity flaw; the vector's S:C (scope change) indicates the compromise crosses a privilege boundary, which is why the sandbox-escape outcome is so consequential. High confidentiality impact means exposure of any data the browser session can reach — webmail, SaaS sessions, intranet portals, saved credentials with autofill. High integrity impact means an attacker can modify that same data or the user's session state. High availability impact permits denial-of-service conditions including browser crashes or host instability as a side effect of exploitation attempts.

Blast radius is driven by the user interaction requirement and the ubiquity of Chrome. Any endpoint running a version below 155.0.8059.39 is potentially affected. Because exploitation executes outside the sandbox, endpoint detection and response coverage on the host — not just browser-level controls — becomes the relevant monitoring plane. No affected OSV packages or version package data were provided; the affected population is defined solely by the Chrome version threshold stated in the NVD description.

Detection Guidance

Sigma Rule

title: Potential Chrome Use-After-Free Exploitation Attempt (CVE-2026-106227)
id: 8f0c1a44-9e6b-4c2f-9c1e-7a2b5d3f0c11
status: experimental
description: Detects suspicious behavior indicative of Chrome renderer compromise and sandbox-escape exploitation attempts against CVE-2026-106227 (CWE-416 use-after-free in Chrome Core).
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-106227
author: Valters IT Threat Intelligence
date: 2026-01-01
tags:
  - attack.t1203
  - attack.execution
logsource:
  category: process_creation
  product: windows
detection:
  selection_parent:
    ParentImage|endswith:
      - '\chrome.exe'
  selection_child:
    Image|endswith:
      - '\cmd.exe'
      - '\powershell.exe'
      - '\wscript.exe'
      - '\cscript.exe'
      - '\mshta.exe'
      - '\rundll32.exe'
      - '\regsvr32.exe'
  filter_chrome_update:
    CommandLine|contains:
      - '--type='
      - 'GoogleUpdater'
  condition: selection_parent and selection_child and not filter_chrome_update
fields:
  - ParentImage
  - Image
  - CommandLine
  - User
falsepositives:
  - Legitimate browser-launched helper processes (rare); tune to environment.
level: high

YARA Rule

rule CVE_2026_106227_Chrome_UAF_Exploit
{
    meta:
        description = "Detects shellcode and exploit artifacts associated with CVE-2026-106227 Chrome use-after-free sandbox escape"
        author = "Valters IT Threat Intelligence"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-106227"
        date = "2026-01-01"
        severity = "high"

    strings:
        $html_marker1 = "<html" ascii nocase wide
        $html_marker2 = "new ArrayBuffer" ascii wide
        $html_marker3 = "WebAssembly" ascii wide
        $shell1 = { 48 31 C0 48 89 C1 48 89 C2 }        // xor rax,rax; mov rcx,rax; mov rdx,rax
        $shell2 = { 65 48 8B 04 25 60 00 00 00 }         // mov rax, gs:[0x60]
        $shell3 = { FC 48 83 E4 F0 E8 C0 00 00 00 }       // common meterpreter/prepend stubs

    condition:
        uint32(0) == 0x46445025 or
        (any of ($shell*) and any of ($html_marker*)) or
        all of ($shell*)
}

Suricata IDS Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2026-106227 Chrome Use-After-Free Exploit Kit Landing Page"; flow:established,to_server; content:"POST"; http_method; content:"User-Agent|3a 20|Mozilla/5.0"; http_header; pcre:"/Chrome\/(1[0-4][0-9]|15[0-4])\.[0-9]+\.[0-9]+\.[0-9]+/H"; classtype:attempted-user; reference:cve,CVE-2026-106227; reference:url,nvd.nist.gov/vuln/detail/CVE-2026-106227; sid:2026106227; rev:1; metadata:created_at 2026_01_01, updated_at 2026_01_01, mitre_tactic_id T1203;)

alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"CVE-2026-106227 Possible Chrome Exploit Delivery HTML Response"; flow:established,from_server; content:"Content-Type|3a 20|text/html"; http_header; content:"application/wasm"; http_header; classtype:attempted-user; reference:cve,CVE-2026-106227; sid:2026106228; rev:1;)

Elastic Detection

sequence by process.entity_id with maxspan=15s
  [process where process.parent.name == "chrome.exe" and event.action == "start"] with runs=1
  [process where process.name in ("cmd.exe", "powershell.exe", "wscript.exe", "mshta.exe", "rundll32.exe") and
   process.parent.name == "chrome.exe"]

Splunk SPL Query

index=endpoint sourcetype=WinEventLog:Security OR sourcetype=WinEventLog:Sysmon
(EventCode=1 OR EventID=1)
| eval parent=coalesce(ParentImage, ParentImageName)
| eval child=coalesce(Image, ImagePath)
| where like(parent, "%\\chrome.exe")
| search child IN ("*\\cmd.exe","*\\powershell.exe","*\\wscript.exe","*\\cscript.exe","*\\mshta.exe","*\\rundll32.exe","*\\regsvr32.exe")
| stats count min(_time) as first_seen max(_time) as last_seen values(CommandLine) as cmdlines by host, user, parent, child
| where count >= 1
| sort - count
| `comment("CVE-2026-106227 - Chrome renderer spawning system processes indicative of sandbox escape")`

Wazuh OSSEC Rule

<group name="chrome,cve-2026-106227,">
  <rule id="1062270" level="12">
    <if_sid>61603</if_sid>
    <field name="win.eventdata.parentImage">\\chrome\.exe$</field>
    <field name="win.eventdata.image">\\(cmd|powershell|wscript|cscript|mshta|rundll32|regsvr32)\.exe$</field>
    <description>CVE-2026-106227: Chrome spawned system process - possible sandbox escape exploitation</description>
    <mitre>
      <id>T1203</id>
    </mitre>
    <group>exploit_attempt,cve_2026_106227,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 0/4 — UNPATCHED — no patch evidence from any tracked source.

1. Immediate mitigations:

   • Treat all Chrome instances below 155.0.8059.39 as potentially exploitable. Confirm the installed version across the fleet; do not rely on auto-update status alone.
   • Apply compensating controls at the network and email layers: block or sandbox untrusted HTML delivery where feasible, and filter suspicious advertisements and watering-hole vectors through secure web gateways.
   • Enable Chrome's Enhanced Safe Browsing and, where policy permits, restrict untrusted sites through enterprise URL filtering.
   • Maintain OS-level endpoint detection on the host plane, since the vulnerability's impact is outside the sandbox and browser-internal telemetry may be insufficient.
   • Reduce the attack surface by disabling unused browser features and extensions and enforcing site isolation where organizationally viable.

2. Patch/upgrade steps:

   • The NVD description identifies version 155.0.8059.39 as the fixed release for Chrome. Upgrade to that version or later as soon as it is available through your distribution channel (Chrome auto-update, Chrome for Enterprise MSI/PKG, or managed package repositories).
   • No vendor fix, workaround, or patch reference was supplied by any tracked source in this intelligence set; validate the fixed version against Google's official Chrome release advisory before deployment.
   • After upgrade, re-verify version uniformity across managed endpoints and mobile clients, and confirm auto-update is functional on remote workers.

3. Long-term hardening:

   • Enforce rapid browser patch SLAs (for example, critical browser patches within 72 hours) since Chrome is a primary attack surface.
   • Deploy application control or browser isolation for high-risk user groups such as executives, finance, and privileged administrators.
   • Instrument process-lineage monitoring for browser processes spawning command interpreters or scripting hosts — this behavior pattern is the most reliable generic signal for sandbox-escape exploitation.
   • Track Chrome security advisories and Chromium severity ratings continuously, and monitor for KEV listing or in-the-wild reporting for this CVE.

References

• NVD — CVE-2026-106227: https://nvd.nist.gov/vuln/detail/CVE-2026-106227
• MITRE CWE-416 — Use After Free: https://cwe.mitre.org/data/definitions/416.html
• MITRE ATT&CK T1203 — Exploitation for Client Execution: https://attack.mitre.org/techniques/T1203/
• Google Chrome Release Notes / Chrome Releases blog (verify fixed version 155.0.8059.39): https://chromereleases.googleblog.com/
• FIRST EPSS — Not yet scored for this CVE at time of writing; check https://api.first.org/data/v1/epss?cve=CVE-2026-106227 for updates.

Note on exploit-in-the-wild evidence: No CISA KEV listing, no public proof-of-concept, no Nuclei template, and no exploit code were present in the supplied intelligence. No threat-actor campaign has been attributed to this CVE in the provided data.