CVE-2026-47312: Samsung Escargot Buffer Overflow Flaw

CVE-2026-47312 Overview

CVE-2026-47312 is a medium-severity vulnerability in Samsung Open Source Escargot, a lightweight JavaScript engine designed for resource-constrained environments. The flaw involves the release of an invalid pointer or reference [CWE-763] during buffer manipulation operations. Successful exploitation requires local access and user interaction, and can lead to high availability impact through process termination or memory corruption. The issue affects the Escargot commit 590345cc6258317c5da850d846ce6baaf2afc2d3. No public exploit is currently available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

Critical Impact

An attacker who convinces a local user to process crafted JavaScript content can trigger an invalid pointer release, causing denial of service or potential memory corruption within the Escargot runtime.

Affected Products

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

Discovery Timeline

• 2026-05-19 - CVE-2026-47312 published to NVD
• 2026-05-19 - Last updated in NVD database

Technical Details for CVE-2026-47312

Vulnerability Analysis

The vulnerability resides in buffer manipulation logic within the Escargot JavaScript engine. Escargot is Samsung's open-source ECMAScript engine optimized for IoT and embedded devices. The defect, classified as [CWE-763] Release of Invalid Pointer or Reference, occurs when the engine releases a pointer that does not reference a valid allocation. This can corrupt heap metadata or cause an immediate crash of the host process.

Exploitation requires the victim to load attacker-controlled JavaScript inside an application that embeds the vulnerable Escargot build. The attack vector is local and demands user interaction, limiting remote exposure. The primary consequence is availability loss; confidentiality and integrity are not directly affected based on the published CVSS vector. Depending on allocator state, the invalid release may also produce undefined behavior that complicates downstream memory safety guarantees.

Root Cause

The root cause is improper lifetime management of a buffer-related pointer. The engine invokes a deallocation routine on a reference that is either uninitialized, already freed, or points outside a valid allocation boundary. Details of the fix are tracked in the upstream Escargot Pull Request #1565, which corrects the pointer handling path involved in buffer manipulation.

Attack Vector

An attacker crafts JavaScript that drives Escargot through a specific buffer manipulation sequence. The victim must execute the script locally, for example by opening a file or launching a vulnerable embedded application. When the engine reaches the defective release path, the process terminates or enters an inconsistent state. There is no network attack surface and no privilege escalation is required from the attacker, but social engineering or supply-chain delivery is necessary to reach the victim.

No verified proof-of-concept code is publicly available. Refer to the upstream patch in the Samsung Escargot GitHub repository for the specific code path corrected by maintainers.

Detection Methods for CVE-2026-47312

Indicators of Compromise

• Unexpected crashes or abnormal termination of processes embedding the Escargot engine
• Heap corruption signatures or SIGSEGV/SIGABRT events tied to Escargot worker threads
• Untrusted JavaScript files arriving through email, removable media, or sideloaded applications on embedded devices

Detection Strategies

• Inventory all firmware, IoT, and application builds that statically or dynamically link Escargot at commit 590345cc6258317c5da850d846ce6baaf2afc2d3 or earlier.
• Run AddressSanitizer (ASan) builds of Escargot in development and QA pipelines to catch invalid free conditions before release.
• Monitor application telemetry for repeated crashes correlated with JavaScript parsing or execution events.

Monitoring Recommendations

• Forward crash reports and core dumps from devices embedding Escargot to a centralized analysis pipeline.
• Alert on anomalous JavaScript file delivery to embedded endpoints, particularly via local file transfer protocols.
• Track upstream commits in the Samsung Escargot repository to detect when remediated builds are deployed across your fleet.

How to Mitigate CVE-2026-47312

Immediate Actions Required

• Rebuild and redeploy applications using an Escargot revision that includes the fix from Pull Request #1565.
• Restrict execution of untrusted JavaScript on devices and applications embedding Escargot until patched builds are deployed.
• Audit third-party SDKs and firmware components for bundled vulnerable Escargot versions.

Patch Information

Samsung addressed the issue in the upstream Escargot repository through Pull Request #1565. Vendors integrating Escargot should pull the corrected commit, rebuild affected products, and distribute updates to deployed devices. Embedded device operators should coordinate with their OEM to obtain patched firmware.

Workarounds

• Disable or gate JavaScript execution features that are not required by the application until a patched build is available.
• Apply application sandboxing and least-privilege execution to limit the impact of a crash in the Escargot process.
• Validate and constrain JavaScript inputs at the application layer, rejecting untrusted scripts from external sources.

# Pull the patched Escargot source and rebuild
git clone https://github.com/Samsung/escargot.git
cd escargot
git fetch origin pull/1565/head:fix-cve-2026-47312
git checkout fix-cve-2026-47312
git submodule update --init --recursive
cmake -H. -Bout/release -DESCARGOT_HOST=linux -DESCARGOT_ARCH=x64 -DESCARGOT_MODE=release
make -Cout/release -j