CVE-2026-58306: Heap Buffer Overflow in Samsung Escargot JavaScript Engine

Technical summary

CVE-2026-58306 is a heap-based buffer overflow (CWE-122) in Samsung Escargot, a JavaScript engine used in embedded and lightweight environments. The vulnerability occurs due to insufficient bounds checking when handling buffer operations. The attack vector is local with no privileges required, but user interaction is necessary to trigger the flaw. The CVSS 3.1 score of 6.1 reflects medium severity, with integrity impact and high availability impact (denial of service through crash), while confidentiality remains unaffected. The vulnerability was resolved in the repository at the specified commit hash.

Business impact

Organizations embedding Escargot in applications or devices face potential service disruption through denial-of-service attacks. Users could encounter application crashes when opening specially crafted content. The availability impact is the primary concern, though integrity of processed data could be compromised. For vendors integrating Escargot into consumer or enterprise products, timely patching is necessary to maintain service reliability and user trust. The local-access requirement limits exposure in purely cloud or network-only deployments, but devices or applications allowing untrusted script execution are at elevated risk.

Affected systems

The vulnerability affects Samsung Escargot JavaScript engine installations prior to commit ef525f337fafddecde77a3c426212a84bb20cb98. Escargot is used in embedded systems, IoT devices, and lightweight application runtimes where a full-featured JavaScript engine is not practical. Products, distributions, or projects that depend on Escargot should verify their version status against the upstream repository. Specific vendor product lists and version numbers should be confirmed via Samsung's official security advisory or the Escargot project repository.

Exploitability

Exploitation is feasible but requires specific conditions. An attacker must achieve local code execution or convince a user to process a malicious input (such as a crafted JavaScript file or webpage). The attack does not require elevated privileges, reducing the barrier to exploitation for authenticated local users or in multi-tenant environments. However, the requirement for user interaction (clicking, opening a file, or visiting a site) provides an opportunity for user awareness training to mitigate risk. No public exploit code or active KEV status indicates the vulnerability is not yet weaponized at scale.

Remediation

Update Escargot to a version incorporating commit ef525f337fafddecde77a3c426212a84bb20cb98 or later. Organizations using Escargot directly should pull the latest upstream code or wait for an official tagged release that includes this fix. Vendors shipping Escargot-based products should coordinate with Samsung or monitor the Escargot project repository for release announcements. In parallel, restrict execution of untrusted scripts, disable JavaScript in untrusted contexts, and isolate Escargot processes to limit blast radius if a crash or corruption occurs.

Patch guidance

Verify the exact version or commit hash of Escargot in your environment by checking repository metadata or application logs. Compare against commit ef525f337fafddecde77a3c426212a84bb20cb98. If your deployment predates this commit, prioritize updating to the patched version. Consult the Escargot project's release notes and Samsung's security advisories for official version tags and download links. Test patched versions in a staging environment to ensure compatibility with your application before deploying to production.

Detection guidance

Monitor for unexpected application crashes or restarts in services running Escargot, particularly following user-supplied input processing. Heap overflow attempts may leave traces in memory dumps or debugger logs. Network-based detection is limited due to the local-access requirement, but endpoint detection and response (EDR) tools can flag abnormal process termination or memory access patterns. Log all JavaScript engine errors and exceptions; unusual patterns may indicate exploitation attempts. Vulnerability scanning tools should flag Escargot versions prior to the patched commit.

Why prioritize this

While the CVSS score of 6.1 is medium, the combination of easy exploitation (no privileges required, user interaction as sole gating factor), high availability impact, and prevalence of Escargot in embedded systems warrants timely patching. Organizations with Escargot-dependent services should treat this as a moderate-priority item, escalating if the affected system is customer-facing, safety-critical, or exposed to untrusted users.

Risk score, explained

The CVSS 3.1 score of 6.1 (Medium) reflects: local attack vector (reduces severity); no privilege escalation needed (increases exploitability); user interaction required (moderate friction); no confidentiality impact; low integrity impact; and high availability impact (application crash/denial of service). The score appropriately captures the balance between ease of triggering and limited scope of direct damage, though business context—such as the criticality of Escargot-dependent processes—may elevate perceived risk.

Frequently asked questions