CVE-2026-106211

Executive Summary

CVE-2026-106211 is a high-severity use-after-free (CWE-416) vulnerability in the TabStrip component of Google Chrome versions prior to 155.0.8059.39. A remote attacker can trigger the flaw by convincing a victim to open a crafted HTML page, potentially achieving arbitrary code execution outside the browser sandbox. With a CVSS base score of 9.6 and a scope-changing impact vector, this represents a critical risk to any organization running unpatched Chrome builds; however, no public proof-of-concept, exploit code, or Nuclei template currently exists, and the CVE has not been added to CISA KEV.

Technical Analysis

The vulnerability is classified as CWE-416 (Use After Free), a memory-safety defect in which a program continues to reference a memory region after it has been freed. In this specific case, the affected code resides within the TabStrip component of Google Chrome. TabStrip is the browser UI subsystem that manages the visual and state representation of browser tabs. The core service involved in the vulnerable interaction — as stated by the NVD description — is that a remote attacker can leverage social engineering to cause arbitrary code execution outside the sandbox via a crafted HTML page.

The attack surface is the rendering and tab-management pathway. A crafted HTML page, when rendered, interacts with the TabStrip code path in a way that causes a heap object to be released while a reference to it is still held. Depending on the precise heap grooming and object type — which are not disclosed in the available NVD data — the attacker may corrupt adjacent heap memory to redirect control flow. Because the CVSS vector indicates S:C (Scope: Changed), successful exploitation crosses a security boundary: code execution is characterized as occurring outside the sandbox, meaning the attacker escapes the renderer sandbox and reaches the browser process or the underlying operating system.

The precise allocation and free sequence, the freed object type, and the specific JavaScript or HTML primitive that triggers the reuse are not described in the NVD entry. No function names, class names, URL endpoints, or parameter names are provided in the source data, and none are fabricated here. What is derivable is the vulnerability class: a memory lifecycle error in a privileged browser component that crosses the sandbox boundary when combined with a renderer compromise primitive.

Chromium security severity is rated High by the vendor, and the CVSS base score is 9.6 (Critical). The high C:H/I:H/A:H subscores reflect total loss of confidentiality, integrity, and availability on the exploited target beyond the sandbox boundary. The AC:L (Attack Complexity: Low) and PR:N (Privileges Required: None) ratings indicate a reliable, unauthenticated path, though UI:R (User Interaction: Required) is what forces the social-engineering prerequisite.

This vulnerability is described in the NVD as fixed in 155.0.8059.39. No patch source, vendor advisory link, or commit reference was supplied in the intelligence data, yielding a patch confidence of 0/4; the fix version is the only patch-related datum available.

Exploitation Scenarios

1. Reconnaissance / Target Identification The attacker identifies targets running Chrome versions below 155.0.8059.39. No authentication or special network position is required (PR:N, AV:N); the only requirement is user interaction (UI:R). Targets are typically identified via drive-by infrastructure, phishing, or malicious advertisements rather than active scanning, since the attack surface is the client browser.

2. Triggering the Flaw The attacker hosts or injects a crafted HTML page. When the victim opens this page — for example by clicking an unsolicited link, visiting a compromised or attacker-controlled site, or rendering a malicious ad — the TabStrip code path in the unpatched Chrome build is exercised in a state that produces a use-after-free. The NVD description confirms the mechanism is a crafted HTML page delivered via social engineering; no specific trigger primitive (e.g., a particular script API or tag sequence) is disclosed in the available data and none is invented here.

3. Payload / Execution at the Vulnerability-Class Level Because CWE-416 is a memory-corruption class, the attacker would, at the class level, attempt to reclaim the freed memory region with attacker-controlled content to influence subsequent operations. The NVD description explicitly states the outcome at the highest level possible: "potentially execute arbitrary code outside the sandbox." This is the key differentiator — a sandbox escape — and it means the exploit chain is not confined to the renderer. No public PoC or exploit code exists for this CVE, so any step-by-step code-level chain is inferred strictly from the vulnerability class and the vendor's description. No public PoC available; attack chain is inferred from vulnerability class.

4. Post-Exploitation Impact Given the scope change (S:C) and high confidentiality, integrity, and availability impact, successful exploitation permits the attacker to run code with the privileges of the exploited Chrome process boundary that lies outside the sandbox — potentially the browser process or the operating system user context. This enables follow-on activity such as credential theft from the browser, arbitrary file manipulation, persistence establishment, and lateral movement within the victim's host. Exact post-exploitation primitives are not described in the NVD data.

Impact Assessment

Business impact is high. Affected systems are any endpoint running Google Chrome earlier than 155.0.8059.39 — desktops, laptops, and potentially any environment where Chrome or Chromium-based browsers are the primary web interface. Because the flaw crosses the sandbox boundary, a single successful exploitation is effectively a workstation compromise, not a browser-tab nuisance.

CVSS subscores:

• AV:N (Network) — exploitable remotely over the network via a crafted page.
• AC:L (Low) — no specialized conditions described; low complexity once interaction is achieved.
• PR:N (None) — no privileges required to attempt exploitation.
• UI:R (Required) — the victim must open the crafted page, hence the social-engineering vector.
• S:C (Changed) — the exploit impacts resources beyond the vulnerable component's authorization scope.
• C:H / I:H / A:H — total loss of confidentiality, integrity, and availability on the affected boundary.

The blast radius is proportional to the population of unpatched Chrome installs. Given the ubiquity of Chrome, even a modest exploitation rate translates to a large number of potentially compromised endpoints. The absence of a public PoC and the fact the CVE is not in CISA KEV currently moderate the immediate threat, but the Critical severity rating and the historically high value of Chrome sandbox-escape chains to both criminal and state-sponsored actors elevate the strategic risk.

Detection Guidance

Sigma Rule

title: Chrome TabStrip Use-After-Free Exploitation Attempt id: 5b1e7a2c-9d4f-4c8b-8a11-106211tab status: experimental description: Detects suspicious post-exploitation behavior consistent with abuse of a Chrome renderer sandbox escape via the TabStrip use-after-free (CVE-2026-106211) references:

• https://nvd.nist.gov/vuln/detail/CVE-2026-106211 author: SOC Threat Intel date: 2026/01/01 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'
  • '\rundll32.exe'
  • '\regsvr32.exe'
  • '\mshta.exe' filter_chrome_helpers: CommandLine|contains:
  • '--type=renderer'
  • '--type=gpu-process'
  • '--type=utility' condition: selection_parent and selection_child and not filter_chrome_helpers fields:
• Image
• ParentImage
• CommandLine
• User falsepositives:
• Legitimate Chrome extensions launching helper processes level: high tags:
• attack.t1204.001
• attack.t1059

YARA Rule

rule EXPL_Chrome_TabStrip_UseAfterFree_2026_106211
{
    meta:
        description = "Heuristic detection of exploit artifacts targeting Chrome TabStrip use-after-free (CVE-2026-106211)"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-106211"
        cve = "CVE-2026-106211"
        author = "SOC Threat Intel"
        date = "2026-01-01"
        severity = "high"

    strings:
        $html1 = "<html" ascii nocase
        $html2 = "<script" ascii nocase
        $ua = "Chrome/" ascii nocase
        $sandbox1 = "sandbox" ascii nocase
        $sandbox2 = "ArrayBuffer" ascii
        $sandbox3 = "SharedArrayBuffer" ascii
        $heap1 = "revokeObjectURL" ascii
        $heap2 = "transferControlToOffscreen" ascii
        $tabref = "TabStrip" ascii
        $tabref2 = "tabstrip" ascii nocase

    condition:
        uint32(0) == 0x464C457F or uint16(0) == 0x5A4D or
        (any of ($html*) and $ua and any of ($sandbox*) and any of ($heap*) and any of ($tabref*))
}

Suricata IDS Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2026-106211 Possible Chrome TabStrip Use-After-Free Exploit Page Fetch"; flow:to_server,established; http.header; content:"User-Agent"; nocase; http.header; content:"Chrome/"; nocase; http.header; content:"<155.0.8059.39"; sid:1062110; rev:1; reference:cve,2026-106211; classtype:attempted-user; metadata:affected_product Google_Chrome, cve CVE-2026-106211;)

Elastic Detection

process where event.type == "start" and process.parent.name : "chrome.exe" and process.name : ("cmd.exe", "powershell.exe", "wscript.exe", "cscript.exe", "rundll32.exe", "mshta.exe") and not process.command_line : ("--type=renderer", "--type=gpu-process", "--type=utility")

Splunk SPL Query

index=endpoint (Image="\chrome.exe" OR ParentImage="\chrome.exe") | eval suspicious_child=if(match(ParentImage, "(?i)chrome\.exe$") AND match(Image, "(?i)(cmd|powershell|wscript|cscript|rundll32|mshta|regsvr32)\.exe$") AND NOT match(CommandLine, "(?i)--type=(renderer|gpu-process|utility)"), 1, 0) | where suspicious_child=1 | stats count min(_time) as first_seen max(_time) as last_seen values(CommandLine) as commandlines by host, User, Image, ParentImage | sort -count

Wazuh OSSEC Rule

61603 chrome\.exe$ (cmd|powershell|wscript|cscript|rundll32|mshta|regsvr32)\.exe$ CVE-2026-106211: Suspicious child process spawned by Chrome (possible sandbox escape via TabStrip use-after-free) T1204.001 T1059 cve_2026_106211,exploit_attempt,

Mitigation & Patch Guidance

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

1. Immediate mitigations

   • Upgrade Google Chrome to 155.0.8059.39 or later as the primary remediation. No vendor workaround is documented in the available intelligence.
   • Where upgrade is not immediately possible: enforce a restrictive allowlist policy on the browser, disable unneeded extensions, and restrict the rendering of untrusted HTML through enterprise browsing controls.
   • Reduce exposure to the social-engineering prerequisite via security awareness training focused on unsolicited links, malvertising, and drive-by pages.
   • Enable browser sandbox hardening, OS-level exploit mitigations (ASLR, DEP/CFG, CET where available), and endpoint detection and response (EDR) coverage on all Chrome-bearing hosts.

2. Patch / upgrade steps

   • Verify the installed Chrome version via chrome://version.
   • Update to 155.0.8059.39 or later through the native updater, enterprise MSI/pkg deployment, or a managed software channel.
   • Confirm the update is applied across all user profiles and that auto-update is functional.
   • Re-scan endpoints to confirm no host remains on a version below 155.0.8059.39.

3. Long-term hardening

   • Enforce browser version minimums through endpoint management and continuous compliance scanning.
   • Adopt a rapid patch cadence for client browsers given their outsized attack surface.
   • Deploy application allowlisting and least-privilege execution on endpoints to blunt post-exploitation impact.
   • Monitor for abnormal process lineage originating from chrome.exe to detect sandbox-escape behaviors early.

References

1. NVD — CVE-2026-106211: https://nvd.nist.gov/vuln/detail/CVE-2026-106211
2. CWE-416 Use After Free: https://cwe.mitre.org/data/definitions/416.html
3. MITRE ATT&CK T1204.001 — User Execution: Malicious Link: https://attack.mitre.org/techniques/T1204/001/
4. CISA Known Exploited Vulnerabilities Catalog (CVE-2026-106211 not listed as of report date): https://www.cisa.gov/known-exploited-vulnerabilities-catalog
5. Chromium security severity guidance: https://www.chromium.org/Home/chromium-security/

No public proof-of-concept, exploit code, Nuclei template, or confirmed in-the-wild exploitation was identified in the supplied intelligence. No specific threat actor campaign has been publicly attributed to CVE-2026-106211 at the time of writing.

◈ SOURCE Analysis & enrichment: valtersit.com/cve/CVE-2026-106211/ · CVE data: NVD/MITRE (public domain) · © 2026 ValtersIT Hub