CVE-2026-124684 in Escargot
Summary
by MITRE • 11/09/2026
Use after free vulnerability in Samsung Open Source Escargot allows Pointer Manipulation.
This issue affects Escargot: before 8bc35b7b88f0f96c66a42aa965a1a710308b61d5.
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Analysis
by VulDB Data Team • 11/09/2026
The vulnerability identified in Samsung Open Source Escargot represents a critical memory safety flaw classified as an use-after-free condition, which directly facilitates arbitrary pointer manipulation within the JavaScript engine's execution environment. This specific defect exists in versions of Escargot prior to commit hash 8bc35b7b88f0f96c66a42aa965a1a710308b61d5, indicating that any deployment utilizing this engine version is susceptible to exploitation through crafted JavaScript payloads. The core of the issue lies in the lifecycle management of internal objects and memory buffers allocated by the garbage collector or explicit allocation routines within the JIT compiler or interpreter components. When an object is freed due to being unreachable or explicitly deleted, the underlying memory block is returned to the system allocator but may not be immediately zeroed out or invalidated from all active references held by the engine's runtime structures.
From a technical perspective, this use-after-free scenario allows an attacker who can execute arbitrary JavaScript code within the Escargot context to access and modify freed memory regions before they are reallocated for other purposes. By carefully controlling the timing of garbage collection cycles and object allocation patterns, it is possible to maintain dangling pointers that reference these deallocated blocks. Once such a pointer remains valid in the engine's internal state despite the logical deletion of the associated high-level JavaScript object, subsequent operations can read from or write to this memory location. This capability effectively breaks the isolation guarantees provided by the sandboxed environment, as it permits direct manipulation of heap metadata, function pointers, and other critical data structures that govern program execution flow.
The operational impact of this vulnerability is severe, primarily because pointer manipulation in a JavaScript engine often leads directly to remote code execution or arbitrary memory read-write primitives. An attacker leveraging this flaw can overwrite vtable pointers, control flow instructions, or security-critical flags within the Escargot process space. This level of control allows for full compromise of the host system if Escargot is running with elevated privileges or when embedded in applications that do not enforce strict sandboxing policies. Furthermore, because JavaScript engines are frequently used to parse and execute untrusted content from web pages or API responses, this vulnerability poses a significant risk to any application integrating Escargot for script evaluation without adequate isolation mechanisms such as WebAssembly sandboxes or process-level containment.
In terms of industry standard classifications, this flaw aligns with CWE-416, which describes Use After Free vulnerabilities where memory is accessed after it has been freed, leading to undefined behavior and potential exploitation. Additionally, the ability to manipulate pointers and achieve arbitrary code execution maps closely to ATT&CK technique T1059, specifically sub-techniques related to command and script interpreters like JavaScript, as well as MITRE CWE-787 for out-of-bounds write if the pointer manipulation results in writing beyond intended boundaries. The exploitation path typically involves crafting a malicious script that triggers specific garbage collection behaviors while maintaining references to freed objects, thereby creating a race condition or state inconsistency that Escargot fails to detect and prevent during execution.
Mitigation strategies must prioritize immediate updates to the latest stable version of Samsung Open Source Escargot where this commit has been integrated, as it likely contains patches for proper reference counting adjustments or nullification of dangling pointers upon deallocation. For environments unable to update immediately, implementing strict Content Security Policies that restrict inline script execution and disabling unnecessary JavaScript features can reduce the attack surface. Additionally, deploying runtime application self-protection mechanisms or memory corruption mitigations such as Address Space Layout Randomization, heap hardening techniques like free-list randomization, and sandboxing Escargot processes with restricted permissions are essential defensive measures to limit the impact of successful exploitation attempts until a permanent code fix is applied across all affected systems.