CVE-2026-58305: Type Confusion in Samsung Escargot JavaScript Engine

Technical summary

CVE-2026-58305 is a type confusion vulnerability (CWE-843) in Samsung Escargot prior to commit 779f6bedf58f334dec64b0a51ebb724b4708b84a. The vulnerability arises when the engine accesses a resource using an incompatible type, creating a window for pointer manipulation. An attacker can craft malicious JavaScript code that exploits this type mismatch to corrupt memory or trigger undefined behavior. The attack vector is local with low complexity, meaning no special privileges are required, but the attacker must trick a user into executing the malicious code.

Business impact

Organizations embedding Escargot in applications face potential service disruptions due to application crashes triggered by malicious input. While the vulnerability does not directly enable remote code execution or data theft, it can lead to denial of service and may serve as a stepping stone in multi-stage attacks. Products using Escargot for embedded scripting (such as IoT devices, smart TVs, or lightweight runtime environments) are particularly vulnerable if they process untrusted JavaScript from external sources.

Affected systems

The vulnerability affects Samsung Escargot open-source JavaScript engine in all versions before commit 779f6bedf58f334dec64b0a51ebb724b4708b84a. Any application, firmware, or service that embeds this engine is potentially affected. Samsung products using Escargot (particularly embedded systems and smart devices) should be assessed for exposure. The vendor product list from official sources should be consulted to identify specific affected devices and applications.

Exploitability

Exploitation requires local access and user interaction, which moderates the attack surface compared to network-based vulnerabilities. An attacker must deliver malicious JavaScript to the target environment—either by convincing a user to open a file, visit a website, or interact with an application that processes untrusted scripts. The attack complexity is low once the malicious payload is in place. However, widespread automated exploitation is unlikely without a clear infection vector; targeted attacks against specific deployments remain feasible.

Remediation

Apply the patch by updating to Escargot version incorporating commit 779f6bedf58f334dec64b0a51ebb724b4708b84a or later. Organizations should verify the exact patched version applicable to their embedded products by consulting Samsung's advisory and release notes. For products where Escargot is embedded, coordinate with vendors to obtain and deploy updates. Until patches are available, restrict execution of untrusted JavaScript and implement code review processes for scripts running in Escargot environments.

Patch guidance

Update Samsung Escargot to the patched version. Verify against Samsung's official advisory to confirm the specific version number or commit hash applicable to your deployment. If Escargot is embedded in third-party applications or devices, contact the respective vendor for their patched release timeline. Prioritize updates for internet-facing or user-input-processing systems. Test patches in a staging environment before production deployment to ensure compatibility with dependent applications.

Detection guidance

Monitor for unexpected application crashes or restarts in systems running Escargot-based applications, especially following user activity. Implement JavaScript input validation and sandboxing where possible. Log JavaScript execution errors and type-related failures. Intrusion detection systems may flag anomalous memory access patterns or pointer dereferences if configured for JavaScript runtime monitoring. Review application telemetry for patterns consistent with type confusion exploitation (e.g., repeated segmentation faults or memory access violations triggered by specific script inputs).

Why prioritize this

While the CVSS score of 6.1 reflects moderate severity, the vulnerability's impact on availability (high) and potential for memory corruption warrant prompt attention. Organizations deploying Escargot in production systems should prioritize patching, particularly if those systems process untrusted scripts or are user-facing. The requirement for user interaction lowers the urgency compared to zero-click attacks, but the ease of exploitation once code is executed and the breadth of potential affected devices (embedded systems, smart TVs, IoT) justify elevated priority in environments with significant Escargot presence.

Risk score, explained

The CVSS 3.1 score of 6.1 (Medium severity) reflects: local attack vector (AV:L) limiting remote exploitation; low attack complexity (AC:L) meaning minimal setup required once code is on the target; no privileges needed (PR:N); requirement for user interaction (UI:R); no scope change (S:U); no confidentiality impact (C:N); low integrity impact (I:L) from pointer manipulation; and high availability impact (A:H) due to crash potential. The score appropriately balances the serious denial-of-service risk against the local-only attack vector and user interaction requirement.

Frequently asked questions