CVE-2026-79010

Executive Summary

CVE-2026-79010 is a use-after-free (UAF) vulnerability in the Network component of Google Chrome, fixed in version 152.0.7977.65. The flaw allows a remote attacker who has already compromised the renderer process to bypass web origin policy via a crafted HTML page, enabling unauthorized cross-origin data access. Affected users include all Chrome desktop and mobile users running versions prior to 152.0.7977.65; exploitation requires user interaction (visiting a malicious page) and prior renderer compromise. Despite a Medium severity rating (CVSS 4.3), the practical impact is amplified by the prerequisite renderer compromise, which lowers the barrier for full origin-policy bypass and potential data exfiltration.

Technical Analysis

Vulnerability Mechanism

CVE-2026-79010 is a use-after-free (UAF) vulnerability (CWE-672: Operation on a Resource After Expiration or Release) located in Chrome's Network component. The precise code paths and function names are not disclosed in the NVD description; therefore, analysis proceeds at the vulnerability-class level.

In Chrome's multi-process architecture, the renderer process handles HTML parsing, JavaScript execution, and network resource fetching. When a renderer process fetches network resources, it interacts with the browser process's Network Service via IPC (Inter-Process Communication). The vulnerability occurs when a network resource object — such as a pending request, a response body, or a websocket state — is released or expires in one thread while another thread (or callback) continues to reference it. This race condition leads to a dangling pointer that can be dereferenced, potentially allowing the attacker to read or manipulate freed memory.

The attack surface is the network fetch path: any resource loaded via HTTP, HTTPS, WebSocket, or Service Worker could trigger the vulnerable code path. Because the trigger is a crafted HTML page, the entry point is any web page loaded in a compromised renderer.

Attack Preconditions

The NVD description specifies that the attacker must have already compromised the renderer process. This is a two-stage attack — not a single-shot remote exploit. Renderer compromise is commonly achieved via a separate Chrome sandbox escape, a V8 JavaScript engine bug, or through abusing a separate renderer-level vulnerability.

The UAF then serves as a privilege escalation / policy bypass primitive within the already-compromised renderer, allowing the attacker to:

1. Bypass the Same-Origin Policy (SOP) – the foundational security boundary in web browsers.
2. Read cross-origin resource responses (e.g., attacker-controlled page reads victim's bank session).

CVSS Analysis

Score: 4.3 (Medium) | Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

• Attack Vector: Network (AV:N) – Exploited via a remote web page.
• Attack Complexity: Low (AC:L) – No race conditions or specialized conditions needed for the UAF trigger itself (beyond renderer compromise).
• Privileges Required: None (PR:N) – Authentication not required.
• User Interaction: Required (UI:R) – Victim must visit the crafted HTML page.
• Scope: Unchanged (S:U) – Vulnerability does not extend beyond the browser.
• Confidentiality: Low (C:L) – Partial cross-origin data disclosure possible.
• Integrity: None (I:N) –** Availability: None (A:N)**.

The Low confidentiality score reflects that full data theft is limited by the prerequisite renderer compromise (which is the primary exploit stage); this CVE is the second-stage primitive.

Patch Status

Patch confidence is 2/4 (CLAIMED) – only NVD lists the fixed version (152.0.7977.65). No vendor advisory or third-party confirmation. Chrome's automatic update mechanism typically pushes fixes within 1–2 weeks; enterprises with managed rollouts should verify update status.

Exploitation Scenarios

No public PoC exists and no exploit code is available. The following attack chain is inferred from the vulnerability class per the NVD description.

Scenario 1: Phishing Campaign for Cross-Origin Data Theft

Prerequisite: Attacker already has a renderer compromise exploit (e.g., a separate V8 bug).

1. Reconnaissance / Target Identification:

   • Attacker identifies a Chrome user with access to sensitive cross-origin data (e.g., corporate webmail, cloud storage, banking portal).
   • Simpler: a broad phishing campaign targeting millions of Chrome users.

2. Flaw Trigger:

   • Victim visits a malicious HTML page (delivered via HTTPS) in the compromised renderer.
   • The page initiates a series of resource fetches (e.g., <img>, fetch(), XMLHttpRequest) designed to race a network object's release against a subsequent dereference.
   • This triggers the UAF in the Network component.

3. Payload / Execution:

   • With a dangling pointer controlled, the attacker crafts a new allocation occupying the freed slot (heap spraying) containing a fake object that leaks memory addresses or file descriptors.
   • The leak provides the attacker with memory layout info and possibly a read primitive.

4. Post-Exploitation Impact:

   • Attacker uses the read primitive to issue cross-origin requests (e.g., fetch('https://target.com/victim-data')) while stripping CORS headers.
   • Response bodies are read directly from the memory pointer, achieving an origin-policy bypass.
   • Data exfiltrated to attacker-controlled endpoint.

Scenario 2: Malvertising / Drive-by Compromise Chain

1. Attacker injects malicious JavaScript into an ad network (malvertising).
2. The ad loads in a compromised renderer (either via UAF from a separate CVE-2026-XXXX or prior session).
3. Uses CVE-2026-79010 to pivot from renderer compromise to network-layer data theft, stealing OAuth tokens and session cookies from other origins.

Remediation of Attack Chain

The UAF does not directly escalate to OS-level compromise by itself (sandbox remains intact), but combined with renderer compromise, it enables credential theft, session hijacking, and corporate espionage.

Impact Assessment

Business Impact

• Data Breach Risk: Cross-origin data exposure can lead to theft of session tokens, PII, financial data, and corporate credentials. A Low confidentiality CVSS sub-score underestimates this in enterprise contexts where a single stolen session can laterally expand.
• Reputational Damage: For organizations running Chrome (e.g., kiosks, managed desktops), an exploit combining renderer compromise + this UAF undermines trust in Chrome as a secure work environment.
• Compliance: Potential GDPR / HIPAA / PCI-DSS violations if the data stolen includes regulated PII or cardholder data.

Affected Systems

• All Chrome browsers on Windows, macOS, Linux, Android, and iOS prior to 152.0.7977.65.
• Chrome-based browsers (Chromium, Microsoft Edge, Brave, Opera) that have not yet backported the fix.
• ChromeOS and other embedded Chrome devices.

Blast Radius

• User base: Over 2 billion active Chrome devices globally.
• Exploitation barrier: Requires prior renderer compromise — a non-trivial step but achievable with packaged exploit kits sold in underground markets.
• EPSS Score: 0.00659 (48.9th percentile of exploited CVEs) — indicates moderate exploitation likelihood; not actively exploited in the wild per CISA KEV (NO).

Detection Guidance

Sigma Rule

title: Chrome Network UAF Exploit Activity - CVE-2026-79010
id: 7c4d9b2e-5f1a-4c7e-9d3b-6a2e8f1c5d4a
status: experimental
description: Detects suspicious Chrome renderer crash patterns and rapid cross-origin fetch activity indicative of CVE-2026-79010 exploitation.
author: Valters IT Threat Intel
date: 2026/06/15
logsource:
    category: process_creation
    product: windows
detection:
    selection_chrome_crash:
        Image|endswith: '\\chrome.exe'
        CommandLine|contains:
            - '--renderer-crash'
            - '--enable-crash-reporter'
    selection_repeat_crash:
        # Chrome logging crash dumps in rapid succession (3+ within 10 min)
        EventID: [1001, 1000]  # Windows Error Reporting
        Application: 'chrome.exe'
    condition: selection_chrome_crash and selection_repeat_crash
    timeframe: 10m
level: high
falsepositives:
    - Legitimate Chrome crashes from plugin bugs (Flash, PDF)
    - Automated Chrome testing frameworks
tags:
    - attack.t1190
    - cve.2026-79010
    - cwe.672

YARA Rule

rule CVE_2026_79010_Chrome_Network_UAF_Exploit {
    meta:
        author = "Valters IT Threat Intel"
        description = "Detects malicious HTML payloads attempting to trigger network UAF in Chrome"
        cve = "CVE-2026-79010"
        cwe = "CWE-672"
        severity = "medium"
        date = "2026-06-15"
    strings:
        $s1 = "fetch(" ascii nocase
        $s2 = "XMLHttpRequest" ascii nocase
        $s3 = "new Option()" ascii nocase
        $s4 = "onerror" ascii nocase
        $s5 = "top.document" ascii nocase  // cross-origin attempt
        $s6 = "postMessage" ascii nocase   // leaking data
        $s7 = "responseText" ascii nocase
        $s8 = "heap" ascii nocase           // heap spraying hint
        $s9 = "\x00\x00\x00\x00" ascii     // null pointer spray pattern
    condition:
        // Multiple fetch/XHR + cross-origin + data leak indicators
        (uint16(0) == 0x5B3C) and  // "<[" - HTML start
        (1 of ($s1, $s2)) and
        (1 of ($s5, $s6, $s7)) and
        ($s3 or $s4) and
        filesize < 200KB
}

Suricata IDS Rule

alert http any any -> any any (msg:"ET EXPLOIT CVE-2026-79010 Chrome Network UAF Origin Bypass Attempt"; flow:established,to_server; content:"fetch("; http_client_body; nocase; content:"XMLHttpRequest"; http_client_body; nocase; pcre:"/(fetch\(|XMLHttpRequest).{0,500}(crossOrigin|targetOrigin|top\.document)/i"; reference:cve,2026-79010; reference:url,https://nvd.nist.gov/vuln/detail/CVE-2026-79010; classtype:attempted-user; sid:2026079010; rev:1;)

Elastic Detection

// Elastic EQL (Endpoint Security / Auditbeat)
sequence by process.entity_id with maxspan=10m
  [network where process.name == "chrome.exe" and
   event.action == "connection_attempted" and
   destination.port == 443 and
   network.protocol == "http"]
  [file where process.name == "chrome.exe" and
   event.action in ("write", "create") and
   file.extension == "dmp" and
   file.size > 1000000]  // chrome crash dumps
  [network where process.name == "chrome.exe" and
   event.action == "connection_attempted" and
   source.ip != destination.ip and
   user_agent.name == "Chrome" and
   // rapid multiple connections (exfil pattern)
   (network.direction == "egress")]

Splunk SPL Query

index=chrome_events OR index=endpoint
| search (process_name="chrome.exe" AND (message="*renderer crash*" OR message="*network error*"))
| transaction host maxspan=10m
| stats count(eval(status="crash")) as crash_count,
          count(eval(event_type="network")) as net_events,
          VALUES(dest_url) as outbound_urls
    by host, user
| where crash_count > 2 AND net_events > 50
| eval threat_score = (crash_count * 2) + (net_events / 100)
| sort threat_score desc
| table _time, host, user, crash_count, net_events, outbound_urls, threat_score

Wazuh OSSEC Rule

<group name="chrome,cve-2026-79010,">
  <!-- Rule: Detect Chrome renderer crashes followed by suspicious network egress -->
  <rule id="274784" level="10">
    <decoded_as>windows_eventlog</decoded_as>
    <field name="EventID">^1000$</field>
    <field name="Application">chrome\.exe</field>
    <description>Google Chrome renderer crash - potential CVE-2026-79010 exploitation</description>
    <group>vulnerability,exploit,cve</group>
    <options>no_full_log</options>
  </rule>

  <rule id="274785" level="12">
    <if_sid>202607901</if_sid>
    <field name="param1">chrome\.exe</field>
    <field name="param2">\.dmp</field>
    <description>CVE-2026-79010: Chrome crash dump generated with network error - investigate origin bypass</description>
    <group>vulnerability,exploit,cve</group>
  </rule>

  <rule id="274786" level="14">
    <if_sid>202607902</if_sid>
    <match>network|http|fetch</match>
    <description>CVE-2026-79010: Confirmed network-layer exploitation pattern - immediate containment</description>
    <group>vulnerability,exploit,cve,pci_dss_11.4</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 2/4 (CLAIMED) — Only NVD confirms the fix; no official Google advisory yet. Treat as high-confidence but verify independently.

1) Immediate Mitigations (if patch cannot be applied immediately)

• Disable or restrict Chrome's Network Service via enterprise policy (--disable-features=NetworkService) — legacy path avoids the vulnerable code but degrades functionality. Not recommended long-term.
• Enforce Strict Site Isolation (chrome://flags/#site-isolation-trial-opt-out) to contain cross-origin damage if renderer is compromised.
• Block third-party cookies and enable Enhanced Protection mode (chrome://settings/security) to reduce tracking-based exfiltration.
• Restrict outbound egress via firewall — allowlist only necessary domains to limit data exfiltration.
• Monitor for renderer crash loops (see detection rules above).

2) Patch / Upgrade Steps

1. Verify current version: chrome://settings/help — ensure version ≥ 152.0.7977.65.
2. Automatic update: Chrome auto-updates; verify in chrome://settings/help that "Update channel" is set to "Stable" and updates are not blocked by group policy.
3. Enterprise managed environments (Windows):
   • Use Google Update for Enterprise (ADMX templates) to force-update Chrome.
   • Push MSI package: chrome_installer.exe with GOOGLE_UPDATE_IS_LOGGED=1.
4. Chromium-based browsers (Edge, Brave, Opera): Check vendor-specific patching; may lag behind Chrome.
5. Verify patch via registry (Windows): HKLM\SOFTWARE\Google\Update\Clients\{8A69D345-D564-463C-AFF1-A69D9E530F96} → pv value ≥ 152.0.7977.65.

3) Long-Term Hardening

• Enable Chrome Enterprise Core (formerly Chrome Browser Cloud Management) for centralized patch enforcement.
• Deploy app-lockout policies — block Chrome versions below the minimum via GPO/system management (e.g., Microsoft Intune, Jamf).
• Include Chrome in CVE-as-code pipeline — integrate NVD/CISA KEV feeds into SIEM alerts for browser vulnerabilities.
• Network segmentation — ensure browsers only access necessary subnets; isolate high-value targets from general browsing.
• Harden renderer sandbox — keep Chrome flags at defaults for higher sandbox fidelity.
• User awareness — train users on phishing and malvertising as the #1 infection vector; report suspicious sites via chrome://safe-browsing.

References

1. NVD Entry: https://nvd.nist.gov/vuln/detail/CVE-2026-79010
2. Google Chrome Release Blog (anticipated): https://chromereleases.googleblog.com/ (search for "Stable Channel Update for Desktop" week of the fix)
3. CISA Known Exploited Vulnerabilities Catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog (CVE-2026-79010 NOT listed — no in-the-wild exploitation confirmed)
4. EPSS Data: https://www.first.org/epss/data_stats (CVE-2026-79010, score 0.00659)
5. Chromium Bug Tracker (if/when public): https://bugs.chromium.org/p/chromium/issues/list

Threat Actor Campaigns / Exploit in the Wild: No known campaigns leveraging CVE-2026-79010 have been reported. CISA KEV does not list it, and no exploit code is available in public repositories. Exploitation would likely occur as part of a targeted RAT (Remote Access Trojan) campaign combining a renderer exploit (e.g., V8 UAF from a separate CVE) with this Network UAF. SOC teams should monitor FireEye/Mandiant, Google TAG (Threat Analysis Group), and MITRE ATT&CK for emerging in-the-wild reporting.