CVE-2026-6306
Published: 15 April 2026
Summary
CVE-2026-6306 is a high-severity Heap-based Buffer Overflow (CWE-122) vulnerability in Google Chrome. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked at the 9.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-2 (Flaw Remediation) and RA-5 (Vulnerability Monitoring and Scanning).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Mandates timely identification, reporting, and patching of flaws like the PDFium heap buffer overflow fixed in Chrome 147.0.7727.101.
Implements memory safeguards such as ASLR and DEP to mitigate heap buffer overflow exploits in PDFium.
Requires vulnerability scanning to identify and prioritize remediation of CVE-2026-6306 in deployed Chrome instances.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Heap buffer overflow in Chrome PDFium enables T1203 (Exploitation for Client Execution) via malicious PDF processing for arbitrary code execution; requires user interaction to open file, mapping to T1204.002 (Malicious File).
NVD Description
Heap buffer overflow in PDFium in Google Chrome prior to 147.0.7727.101 allowed a remote attacker to execute arbitrary code inside a sandbox via a crafted PDF file. (Chromium security severity: High)
Deeper analysisAI
CVE-2026-6306 is a heap buffer overflow vulnerability (CWE-122) in the PDFium component of Google Chrome versions prior to 147.0.7727.101. This flaw allows a remote attacker to potentially execute arbitrary code within the browser's sandbox when a user processes a specially crafted PDF file. The vulnerability carries a CVSS v3.1 base score of 8.8, classified as High severity by Chromium security standards.
A remote attacker can exploit this issue without privileges by tricking a user into opening a malicious PDF file, such as via email, web download, or other vectors requiring user interaction. Successful exploitation enables arbitrary code execution confined to the sandbox, granting high impacts on confidentiality, integrity, and availability (C:H/I:H/A:H) while maintaining unchanged scope (S:U).
Chrome's stable channel update addresses this vulnerability in version 147.0.7727.101 and later, as detailed in the official release notes at https://chromereleases.googleblog.com/2026/04/stable-channel-update-for-desktop_15.html. Additional technical details are available in the Chromium issue tracker at https://issues.chromium.org/issues/496907110. Security practitioners should prioritize updating affected Chrome installations to mitigate risks.
Details
- CWE(s)