External risk intelligence

Apache Syncope Groovy Sandbox Bypass Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-113687

The vulnerability requires an administrator with existing entitlements to Implementations to execute malicious code. While Apache Syncope serves identity management functions, this specific attack path requires pre-existing administrative access rather than being a public-facing, unauthenticated entry point, making exploitation via the public internet unlikely in typical deployments.

Halo Surface Signal: 2 out of 5 — less likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

An improper isolation vulnerability in Apache Syncope allows an administrator to bypass security sandboxes and run untrusted code. This could potentially impact the integrity and availability of identity management functions if exploited.

  • Malicious code can bypass Syncope's security controls.
  • Administrators with existing access could be targeted.
  • Confirm relevance and potential exposure within your environment.

Attack Path

How an attacker could exploit the issue

An attacker with administrative access to Apache Syncope's Implementations feature could create a malicious Groovy class. This allows them to bypass security restrictions and run untrusted code on a separate thread, potentially leading to significant compromise.

  • Requires administrative access to Implementations.
  • Bypasses the Groovy security sandbox.
  • Leads to untrusted code execution.

Live Threat

Current exploitation, exposure, and threat context

An administrator with adequate entitlements for Implementations could create a malicious Groovy class that runs untrusted code on a separate thread, bypassing the Groovy security sandbox. This could allow for unauthorized actions within the system when supported by the advisory.

  • System data and service behavior.
  • Malicious code execution.
  • Unauthorized system actions.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability in Apache Syncope impacts administrators with sufficient entitlements. The first step is to identify all Apache Syncope instances, confirm their business criticality and external reachability, and then assign ownership for remediation planning.

  • Own by implementation owners and platform teams.
  • Verify Syncope instances and admin access.
  • Plan remediation based on identified risk.

Supplementary metadata

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

Frequently asked questions

What is Apache Syncope and how is it used?

Apache Syncope is an open-source identity and access management system. Organizations use it to manage digital identities, handle user provisioning, and synchronize data across various enterprise applications and IT environments.

What does CWE-653 mean for CVE-2026-113687?

CWE-653 refers to improper insulation or compartmentalization. In the context of this vulnerability, it means the software fails to effectively wall off user-provided logic from the rest of the system. Specifically, it allows malicious Groovy code to break out of its intended secure environment.

How does an attacker trigger this vulnerability?

The vulnerability requires an actor who already holds administrative privileges over the Implementations feature within Apache Syncope. It cannot be triggered by an unauthenticated user or through standard application usage; it relies on the ability to define and execute custom Groovy classes.

Why should I care if my Syncope instance is internal?

Halo Surface Signal indicates that because this flaw requires existing administrative entitlements rather than unauthenticated network access, its likelihood of being exploited via the public internet is low. However, internal threats or compromised admin accounts remain a relevant concern for system integrity.

How do I respond to CVE-2026-113687?

Start by identifying all deployed Apache Syncope instances and verifying who has administrative access to the Implementations feature. The primary remediation is to upgrade your instances to version 4.0.9 or 4.1.4, which specifically address the sandbox bypass.

References