CVE-2026-13281: Chrome Integer Overflow Sandbox Escape – CVSS 8.3 High

Technical summary

This vulnerability stems from an integer overflow condition in Mojo, Chrome's inter-process communication framework. The flaw exists in Chrome versions prior to 149.0.7827.201. The integer overflow occurs during processing of specially crafted file inputs when the renderer process has already been compromised by an attacker. The vulnerability is classified under CWE-472 (Integer Overflow to Buffer Overflow). The CVSS 3.1 score of 8.3 reflects the high potential impact: an attacker with renderer-level code execution can leverage this to break out of Chrome's sandboxing model and achieve arbitrary code execution at the system level. The attack requires network accessibility (AV:N), high complexity (AC:H), no privileges (PR:N), and user interaction (UI:R), but results in complete compromise of confidentiality, integrity, and availability (C:H/I:H/A:H) with scope changes (S:C).

Business impact

Exploitation of this vulnerability could allow attackers to completely compromise systems running vulnerable Chrome versions. Once an attacker has escaped the sandbox, they can execute arbitrary code with the privileges of the user running Chrome, potentially leading to data theft, malware installation, lateral movement within corporate networks, and system takeover. For organizations that rely on Chrome for web access or web applications, this represents a critical risk to endpoint security and data confidentiality. The two-stage nature of the attack—requiring both renderer compromise and successful sandbox escape—raises the bar slightly but does not substantially reduce risk given the prevalence of renderer exploits in the wild.

Affected systems

Google Chrome versions prior to 149.0.7827.201 are directly affected on all supported operating systems: Windows, macOS, and Linux. The vulnerability also indirectly affects systems running these operating systems where Chrome is deployed. Users of Chromium-based browsers that incorporate the vulnerable Mojo code may also be at risk; verify with your browser vendor if you use alternatives like Edge or Brave.

Exploitability

Exploitation requires two preconditions: (1) the renderer process must already be compromised by the attacker, and (2) the user must open a malicious file while the compromised renderer is active. This staged attack model means exploitability is not trivial—an attacker cannot exploit this in isolation. However, renderer vulnerabilities are discovered and exploited regularly, and combining a renderer exploit with this sandbox escape significantly increases the damage potential. The vulnerability is not listed on CISA's Known Exploited Vulnerabilities (KEV) catalog as of the publication date, suggesting active exploitation has not yet been widely documented; however, this does not guarantee a public exploit does not exist.

Remediation

Update Google Chrome to version 149.0.7827.201 or later as soon as possible. Chrome's auto-update mechanism typically deploys patches automatically, but users should verify their version in Chrome Settings > About Chrome. Organizations should enforce Chrome updates through group policy (Windows), Mobile Device Management, or configuration profiles (macOS/Linux). Test patches in a limited environment first if your organization has strict change-management protocols. For users unable to update immediately, minimize risk by avoiding untrusted file downloads and limiting Chrome's exposure to untrusted web content.

Patch guidance

Google has released Chrome 149.0.7827.201 to address this vulnerability. Verify this version number against the official Chrome release notes on the Chromium security page. Deploy patches through your standard mechanisms: auto-update for consumer deployments, or managed enterprise channels for managed Chrome Browser. Monitor your Chrome version inventory to confirm patch adoption. If you maintain a Chromium fork or use a Chromium-based browser, check with your vendor for patched versions that incorporate this fix. Third-party developers embedding Chromium should update to a Chrome version that includes this patch or apply the corresponding upstream Chromium fix.

Detection guidance

Monitor for Chrome version compliance across your organization using Mobile Device Management, System Center, or other asset inventory tools to ensure all devices are running 149.0.7827.201 or later. At the endpoint level, look for sandbox escape indicators: processes spawned by the Chrome or Chromium executable that run outside the sandbox context, unexpected system-level privilege escalation tied to browser activity, or suspicious file access patterns following file downloads. Network-based detection is limited due to the attack's dependence on a malicious file; focus on post-compromise behavior. If you suspect exploitation, check for signs of renderer compromise (e.g., crashes, unexpected browser behavior, successful command execution from web content) in combination with subsequent system-level anomalies.

Why prioritize this

This vulnerability warrants high priority patching due to its CVSS score of 8.3, HIGH severity classification, and potential for complete system compromise via sandbox escape. While the two-stage attack model (renderer compromise + sandbox escape) slightly reduces immediate risk compared to a direct remote code execution, the combination is dangerous and likely to be exploited once renderer vulnerabilities are chained with this flaw. The broad platform coverage (Windows, macOS, Linux) means the patch applies to most Chrome deployments. Prioritize patching within 2–4 weeks, or immediately if you operate in high-risk sectors or manage systems handling sensitive data.

Risk score, explained

The CVSS 3.1 score of 8.3 (HIGH) reflects the severity of potential impact: complete confidentiality, integrity, and availability compromise with scope change. The attack vector is network-based, but attack complexity is high due to the requirement for prior renderer compromise. User interaction is required (a user must open a file). The high complexity and user-interaction requirements prevent a critical score, but the severity of impact—full system compromise—justifies the HIGH rating. Organizations should treat this as a critical patch target despite the complexity factors.

Frequently asked questions