CVE-2026-47313: Samsung Escargot Buffer Overflow Flaw

CVE-2026-47313 Overview

CVE-2026-47313 is a memory allocation vulnerability affecting Samsung Open Source Escargot, a lightweight JavaScript engine designed for resource-constrained environments. The issue allows an attacker to trigger excessive memory allocation by supplying a crafted size value, leading to resource exhaustion and denial of service. The flaw is tracked under [CWE-789: Memory Allocation with Excessive Size Value]. Exploitation requires local access and user interaction, and the vulnerability affects Escargot commit 590345cc6258317c5da850d846ce6baaf2afc2d3.

Critical Impact

Successful exploitation results in high availability impact through memory exhaustion, causing the Escargot JavaScript engine and its host application to terminate or become unresponsive.

Affected Products

• Samsung Open Source Escargot JavaScript engine
• Escargot at commit 590345cc6258317c5da850d846ce6baaf2afc2d3
• Applications and embedded systems integrating the affected Escargot build

Discovery Timeline

• 2026-05-19 - CVE CVE-2026-47313 published to NVD
• 2026-05-19 - Last updated in NVD database

Technical Details for CVE-2026-47313

Vulnerability Analysis

The vulnerability resides in Escargot's memory allocation logic, where an attacker-controlled size value reaches an allocation routine without sufficient bounds validation. When the engine processes specially crafted JavaScript input, the size parameter passed to an internal allocator can be inflated beyond reasonable limits. The allocator then attempts to reserve a large memory region, exhausting available memory and forcing the host process to crash or terminate. The condition is categorized under [CWE-789], which covers cases where software allocates memory based on an untrusted size value without verifying that the request is reasonable.

The attack vector is local and requires user interaction, such as opening or executing a malicious script file in a context that uses Escargot. There is no confidentiality or integrity impact, but availability is directly affected because the engine cannot recover gracefully from the failed allocation attempt.

Root Cause

The root cause is missing validation of size inputs before memory allocation operations. The affected commit lacks a sanity check that constrains allocation requests to a maximum permissible size, allowing JavaScript-controlled values to drive the allocator into pathological behavior.

Attack Vector

An attacker delivers a crafted JavaScript payload to a target system running an Escargot-based application. When the user executes the script, the engine parses an operation that allocates memory using the attacker-controlled size. The allocation request consumes excessive memory and triggers process termination. Technical details and the proposed fix are discussed in the GitHub Pull Request Discussion.

No verified exploit code is publicly available for this issue. The vulnerability mechanism is described in the upstream pull request linked above, which documents the allocation path and the bounds check introduced to address the flaw.

Detection Methods for CVE-2026-47313

Indicators of Compromise

• Unexpected termination or out-of-memory errors in processes embedding the Escargot JavaScript engine.
• Sudden spikes in resident memory usage by Escargot host applications immediately before a crash.
• Crash dumps referencing Escargot allocation routines or GC_MALLOC-style functions with abnormally large size arguments.

Detection Strategies

• Monitor host processes for abnormal memory growth patterns correlated with JavaScript file execution.
• Inspect logs from Escargot-integrated applications for allocation failures or assertion violations.
• Compare deployed Escargot binaries against commit 590345cc6258317c5da850d846ce6baaf2afc2d3 to identify vulnerable builds.

Monitoring Recommendations

• Track per-process memory ceilings and trigger alerts when Escargot-based processes approach configured limits.
• Log and review all untrusted JavaScript inputs delivered to embedded Escargot runtimes.
• Watch for repeated crash-restart cycles in services that load user-supplied scripts.

How to Mitigate CVE-2026-47313

Immediate Actions Required

• Identify all systems and applications that embed Escargot and confirm whether they use the affected commit.
• Restrict execution of untrusted JavaScript files in environments that rely on vulnerable Escargot builds.
• Apply per-process memory limits to contain the impact of excessive allocation attempts.

Patch Information

The fix is tracked in the upstream repository under the GitHub Pull Request Discussion. Rebuild Escargot from a commit that incorporates the validation patch and redeploy affected applications. Vendors that ship products embedding Escargot should integrate the patched engine into their next release cycle.

Workarounds

• Enforce operating system level memory limits (for example, ulimit -v on Linux) on processes that execute Escargot.
• Sandbox Escargot-based interpreters using cgroups or container resource constraints to bound memory consumption.
• Block delivery of untrusted JavaScript content to affected runtimes until the patched engine is deployed.

# Configuration example: constrain memory available to an Escargot host process
ulimit -v 524288   # cap virtual memory at 512 MB
systemd-run --scope -p MemoryMax=512M /usr/local/bin/escargot-host script.js