CVE-2026-92259 in Escargot
Summary
by MITRE • 09/16/2026
Integer overflow or wraparound vulnerability in Samsung Opensource Escargot allows attackers with write access to the bytecode-cache directory to cause a heap-based buffer overflow and denial of service via a crafted cache file.
This issue affects Escargot: ac94df78493ee6fede286620d94f724e46b4d238.
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Analysis
by VulDB Data Team • 09/16/2026
The vulnerability identified in Samsung's Opensource Escargot JavaScript engine represents a critical security flaw rooted in improper handling of integer arithmetic during the processing of cached bytecode files. Specifically, an integer overflow or wraparound condition occurs when the application calculates buffer sizes or offsets based on data derived from untrusted input within the bytecode cache structure. This mathematical error leads to the allocation of a significantly smaller memory buffer than required for storing the parsed content. When the engine subsequently attempts to write the full extent of the processed data into this undersized heap-allocated region, it triggers a heap-based buffer overflow. The root cause lies in the failure to validate that arithmetic operations involving file sizes or array lengths do not exceed the maximum representable value for the integer type used, allowing negative values or small positive wraparounds to bypass size checks and result in insufficient memory allocation.
The operational impact of this vulnerability is severe, primarily manifesting as a denial of service against systems relying on Escargot for JavaScript execution. By crafting a malicious cache file that exploits the integer overflow, an attacker can corrupt adjacent heap metadata or overwrite critical program data structures. This corruption typically results in immediate application crashes, leading to availability loss for any services dependent on the engine. While the primary vector described involves causing instability through memory corruption, such buffer overflows are frequently precursors to more sophisticated attacks if additional exploitation techniques are applied. The ability to write arbitrary data beyond allocated boundaries can potentially allow an attacker to achieve remote code execution by controlling return addresses or function pointers within the heap layout, although the immediate and guaranteed effect is system destabilization and service interruption.
The attack vector requires that the adversary possesses write access to the bytecode-cache directory where Escargot stores its compiled scripts. This constraint implies that the vulnerability is not remotely exploitable over a network without prior compromise of local file systems or user privileges sufficient to inject files into this specific location. Consequently, the threat model focuses on insider threats, compromised accounts with limited filesystem permissions, or scenarios where untrusted content can be persisted in cache directories through other application logic flaws. The presence of write access is a critical prerequisite, as Escargot reads these cached bytecode files during subsequent execution phases to optimize performance by avoiding re-parsing source code. An attacker leveraging this flaw does not need direct network exposure but must have the ability to place crafted artifacts into the designated cache path on the host system.
Mitigation strategies should prioritize both immediate remediation and long-term architectural improvements. The most effective solution is to apply vendor-provided patches that address the integer overflow logic within the bytecode parsing routines, ensuring that all size calculations are validated against maximum limits before memory allocation occurs. In environments where patching is not immediately feasible, administrators can mitigate risk by restricting file system permissions on the bytecode-cache directory so that only trusted processes with elevated privileges can write to it, thereby preventing unprivileged users or compromised services from injecting malicious cache files. Additionally, implementing strict input validation and sanitization for any data sources feeding into the caching mechanism can reduce the attack surface. From a defensive posture perspective, enabling heap protection mechanisms such as Address Sanitizer during development and deployment testing can help detect these types of memory corruption issues early in the software lifecycle before they reach production environments.
This vulnerability aligns with Common Weakness Enumeration (CWE) categories including CWE-190 Integer Overflow or Wraparound and CWE-787 Out-of-bounds Write, which describe the fundamental arithmetic failure and its resulting memory safety violation respectively. In terms of tactical classification under the MITRE ATT&CK framework, this flaw facilitates Initial Access via Local File Inclusion if an attacker can place files in cache directories, followed by Execution through potential code injection or Denial of Service as a direct outcome of heap corruption. Understanding these mappings helps security teams contextualize the risk within broader threat landscapes and prioritize remediation efforts based on established industry standards for vulnerability management and secure coding practices.