CVE-2026-113066 in Chrome
Summary
by MITRE • 10/21/2026
Memory corruption in Fonts in Google Chrome prior to 156.0.8078.47 allowed a remote attacker to read memory inside the sandbox via a crafted HTML page. (Chromium security severity: Low)
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Analysis
by VulDB Data Team • 10/21/2026
The vulnerability identified involves a critical memory corruption flaw within the font rendering subsystem of Google Chrome, specifically affecting versions prior to 156.0.8078.47. This issue stems from improper handling of data structures associated with font files processed by the browser's graphics engine. When a user visits a maliciously crafted HTML page containing specially constructed font resources or CSS rules that trigger complex font rendering operations, the application fails to correctly validate memory boundaries during the parsing and layout phases. This lack of rigorous bounds checking allows an attacker to write data beyond allocated buffer limits, leading to heap corruption. The severity is classified as low by Chromium security standards because while the underlying mechanism involves memory safety violations typical of high-severity vulnerabilities, the specific exploitation path in this instance was constrained enough that it primarily facilitated information disclosure rather than arbitrary code execution or full sandbox escape at a critical level.
From a technical perspective, the core flaw resides in how Chrome processes font data during the composition and rasterization stages. Font files often contain complex tables and glyph definitions that require dynamic memory allocation for rendering purposes. In this specific case, an off-by-one error or similar boundary miscalculation occurs when calculating offsets within these structures. This allows a remote attacker to overwrite adjacent memory regions with controlled values. While modern browsers employ robust sandboxing mechanisms such as site isolation and process separation to mitigate the impact of such flaws, the ability to read arbitrary memory locations inside the sandbox represents a significant breach of confidentiality guarantees. The vulnerability does not directly allow for code execution but provides the attacker with a mechanism to leak sensitive data stored in adjacent memory blocks, which may include session cookies, authentication tokens, or other private user information.
The operational impact of this vulnerability is primarily centered on unauthorized access to confidential browser state and potentially cross-site scripting implications if combined with other flaws. An attacker hosting a malicious webpage can exploit this condition by inducing the victim's Chrome instance to process the crafted font data. Upon successful exploitation, the attacker gains the ability to read memory contents from within the renderer sandbox. This capability undermines the principle of least privilege enforced by the browser architecture, as it allows data exfiltration that was previously isolated from untrusted web content. Although the severity is rated low due to the difficulty in achieving reliable exploitation and the limited scope of access granted, any ability to bypass sandbox isolation poses a risk to user privacy and security integrity. The vulnerability highlights the persistent challenges in maintaining memory safety within complex rendering engines that handle diverse and potentially malicious input formats.
Mitigation strategies for this issue are straightforward given its resolution status. Users must update their Google Chrome installation to version 156.0.8078.47 or later, where the underlying font processing logic has been patched to include proper bounds checking and memory validation routines. For organizations managing large fleets of devices, automated patch management systems should be configured to prioritize this specific security update. Additionally, while not a direct fix for this software flaw, employing browser hardening techniques such as disabling JavaScript in untrusted environments or using extensions that restrict font loading can provide an additional layer of defense against similar exploitation attempts until the official patch is applied. Security teams should also monitor for any indicators of compromise related to unusual memory access patterns or data exfiltration activities that might suggest attempted exploitation of this vulnerability before patches are deployed.
This incident aligns with common weakness enumeration standards, specifically reflecting characteristics associated with improper input validation and buffer overflows in system resources. In the context of cyber kill chain frameworks like MITRE ATT&CK, this vulnerability facilitates initial access through social engineering or drive-by download tactics by leveraging a trusted application to execute malicious code logic indirectly via memory corruption. It also relates to techniques involving data exfiltration from local systems where sensitive information is gathered and sent to external command and control infrastructure. The resolution underscores the importance of continuous security auditing in core browser components, particularly those handling complex binary formats like fonts, which are frequent targets for fuzzing-based vulnerability discovery. Maintaining up-to-date software versions remains the most effective defense against such remotely exploitable memory safety issues.